112 practice sets, each with a complete answer key.

Choose foundations, extension, or mixed review. Every four-page PDF contains seven developed problems, generous working space, and concise solutions that explain the method rather than listing only an answer.

Built for actual practice 5-10 question target: each current set contains 7.
112 practice sets Open teaching decks
Number Theory Foundations Beginner friendly 7 questions
Number TheoryMathematics

Modular Arithmetic: Foundations

Seven foundations problems with complete solutions for modular arithmetic.

Published September 7, 2025 Open set + key
Number Theory Extension Beginner friendly 7 questions
Number TheoryMathematics

Modular Arithmetic: Extension

Seven extension problems with complete solutions for modular arithmetic.

Published September 9, 2025 Open set + key
Networks Foundations Beginner friendly 7 questions
Graph TheoryMathematicsComputer Science

Graph Theory: Foundations

Seven foundations problems with complete solutions for graph theory.

Published September 12, 2025 Open set + key
Networks Extension Beginner friendly 7 questions
Graph TheoryMathematicsComputer Science

Graph Theory: Extension

Seven extension problems with complete solutions for graph theory.

Published September 13, 2025 Open set + key
Counting Foundations AMC / enrichment 7 questions
CountingCombinatoricsMathematics

Combinatorics: Foundations

Seven foundations problems with complete solutions for combinatorics.

Published September 18, 2025 Open set + key
Counting Extension AMC / enrichment 7 questions
CountingCombinatoricsMathematics

Combinatorics: Extension

Seven extension problems with complete solutions for combinatorics.

Published September 24, 2025 Open set + key
Proof Foundations Intermediate 7 questions
Proof

Proof and Induction: Foundations

Seven foundations problems with complete solutions for proof and induction.

Published September 25, 2025 Open set + key
Proof Extension Intermediate 7 questions
Proof

Proof and Induction: Extension

Seven extension problems with complete solutions for proof and induction.

Published September 29, 2025 Open set + key
Algebra + Computing Foundations Intermediate 7 questions
Algebra + Computing

Monoids: Foundations

Seven foundations problems with complete solutions for monoids.

Published October 3, 2025 Open set + key
Algebra + Computing Extension Intermediate 7 questions
Algebra + Computing

Monoids: Extension

Seven extension problems with complete solutions for monoids.

Published October 4, 2025 Open set + key
Applied Math Foundations Intermediate 7 questions
Applied MathMathematics

Applied Optimization: Foundations

Seven foundations problems with complete solutions for applied optimization.

Published October 6, 2025 Open set + key
Applied Math Extension Intermediate 7 questions
Applied MathMathematics

Applied Optimization: Extension

Seven extension problems with complete solutions for applied optimization.

Published October 7, 2025 Open set + key
Probability Foundations Beginner to intermediate 7 questions
ProbabilityMathematics

Expected Value: Foundations

Seven foundations problems with complete solutions for expected value.

Published October 9, 2025 Open set + key
Probability Extension Beginner to intermediate 7 questions
ProbabilityMathematics

Expected Value: Extension

Seven extension problems with complete solutions for expected value.

Published October 20, 2025 Open set + key
Problem Solving Foundations Intermediate 7 questions
Problem Solving

Invariants: Foundations

Seven foundations problems with complete solutions for invariants.

Published October 21, 2025 Open set + key
Problem Solving Extension Intermediate 7 questions
Problem Solving

Invariants: Extension

Seven extension problems with complete solutions for invariants.

Published October 27, 2025 Open set + key
Number Theory Foundations Beginner to intermediate 7 questions
Number TheoryMathematics

Euclidean Algorithm: Foundations

Seven foundations problems with complete solutions for euclidean algorithm.

Published November 1, 2025 Open set + key
Number Theory Extension Beginner to intermediate 7 questions
Number TheoryMathematics

Euclidean Algorithm: Extension

Seven extension problems with complete solutions for euclidean algorithm.

Published November 2, 2025 Open set + key
Number Theory Foundations Beginner friendly 7 questions
Number TheoryMathematics

Prime Factorization: Foundations

Seven foundations problems with complete solutions for prime factorization.

Published November 5, 2025 Open set + key
Number Theory Extension Beginner friendly 7 questions
Number TheoryMathematics

Prime Factorization: Extension

Seven extension problems with complete solutions for prime factorization.

Published November 10, 2025 Open set + key
Number Theory Foundations Intermediate 7 questions
Number TheoryMathematics

Linear Diophantine Equations: Foundations

Seven foundations problems with complete solutions for linear diophantine equations.

Published November 11, 2025 Open set + key
Number Theory Extension Intermediate 7 questions
Number TheoryMathematics

Linear Diophantine Equations: Extension

Seven extension problems with complete solutions for linear diophantine equations.

Published November 15, 2025 Open set + key
Number Theory Foundations Intermediate 7 questions
Number TheoryMathematics

Chinese Remainder Theorem: Foundations

Seven foundations problems with complete solutions for chinese remainder theorem.

Published November 19, 2025 Open set + key
Number Theory Extension Intermediate 7 questions
Number TheoryMathematics

Chinese Remainder Theorem: Extension

Seven extension problems with complete solutions for chinese remainder theorem.

Published November 20, 2025 Open set + key
Number Theory Foundations Intermediate 7 questions
Number TheoryMathematics

Fermat and Euler Theorems: Foundations

Seven foundations problems with complete solutions for fermat and euler theorems.

Published November 23, 2025 Open set + key
Number Theory Extension Intermediate 7 questions
Number TheoryMathematics

Fermat and Euler Theorems: Extension

Seven extension problems with complete solutions for fermat and euler theorems.

Published December 2, 2025 Open set + key
Number Theory Foundations Beginner friendly 7 questions
Number TheoryMathematics

Base Representations: Foundations

Seven foundations problems with complete solutions for base representations.

Published December 9, 2025 Open set + key
Number Theory Extension Beginner friendly 7 questions
Number TheoryMathematics

Base Representations: Extension

Seven extension problems with complete solutions for base representations.

Published December 20, 2025 Open set + key
Counting Foundations Beginner friendly 7 questions
CountingCombinatoricsMathematics

Pigeonhole Principle: Foundations

Seven foundations problems with complete solutions for pigeonhole principle.

Published December 24, 2025 Open set + key
Counting Extension Beginner friendly 7 questions
CountingCombinatoricsMathematics

Pigeonhole Principle: Extension

Seven extension problems with complete solutions for pigeonhole principle.

Published December 26, 2025 Open set + key
Counting Foundations Intermediate 7 questions
CountingCombinatoricsMathematics

Inclusion-Exclusion: Foundations

Seven foundations problems with complete solutions for inclusion-exclusion.

Published December 31, 2025 Open set + key
Counting Extension Intermediate 7 questions
CountingCombinatoricsMathematics

Inclusion-Exclusion: Extension

Seven extension problems with complete solutions for inclusion-exclusion.

Published January 4, 2026 Open set + key
Counting Foundations Beginner to intermediate 7 questions
CountingCombinatoricsMathematics

Binomial Coefficients: Foundations

Seven foundations problems with complete solutions for binomial coefficients.

Published January 9, 2026 Open set + key
Counting Extension Beginner to intermediate 7 questions
CountingCombinatoricsMathematics

Binomial Coefficients: Extension

Seven extension problems with complete solutions for binomial coefficients.

Published January 14, 2026 Open set + key
Sequences Foundations Intermediate 7 questions
AlgebraMathematics

Recurrence Relations: Foundations

Seven foundations problems with complete solutions for recurrence relations.

Published January 15, 2026 Open set + key
Sequences Extension Intermediate 7 questions
AlgebraMathematics

Recurrence Relations: Extension

Seven extension problems with complete solutions for recurrence relations.

Published January 19, 2026 Open set + key
Sequences Foundations Advanced enrichment 7 questions
AlgebraMathematics

Generating Functions: Foundations

Seven foundations problems with complete solutions for generating functions.

Published January 20, 2026 Open set + key
Sequences Extension Advanced enrichment 7 questions
AlgebraMathematics

Generating Functions: Extension

Seven extension problems with complete solutions for generating functions.

Published January 24, 2026 Open set + key
Counting Foundations Advanced enrichment 7 questions
CountingCombinatoricsMathematics

Catalan Numbers: Foundations

Seven foundations problems with complete solutions for catalan numbers.

Published January 29, 2026 Open set + key
Counting Extension Advanced enrichment 7 questions
CountingCombinatoricsMathematics

Catalan Numbers: Extension

Seven extension problems with complete solutions for catalan numbers.

Published January 31, 2026 Open set + key
Networks Foundations Intermediate 7 questions
Graph TheoryMathematicsComputer Science

Trees and Spanning Trees: Foundations

Seven foundations problems with complete solutions for trees and spanning trees.

Published February 2, 2026 Open set + key
Networks Extension Intermediate 7 questions
Graph TheoryMathematicsComputer Science

Trees and Spanning Trees: Extension

Seven extension problems with complete solutions for trees and spanning trees.

Published February 5, 2026 Open set + key
Networks Foundations Intermediate 7 questions
Graph TheoryMathematicsComputer Science

Planar Graphs: Foundations

Seven foundations problems with complete solutions for planar graphs.

Published February 7, 2026 Open set + key
Networks Extension Intermediate 7 questions
Graph TheoryMathematicsComputer Science

Planar Graphs: Extension

Seven extension problems with complete solutions for planar graphs.

Published February 11, 2026 Open set + key
Networks Foundations Intermediate 7 questions
Graph TheoryMathematicsComputer Science

Graph Coloring: Foundations

Seven foundations problems with complete solutions for graph coloring.

Published February 13, 2026 Open set + key
Networks Extension Intermediate 7 questions
Graph TheoryMathematicsComputer Science

Graph Coloring: Extension

Seven extension problems with complete solutions for graph coloring.

Published February 14, 2026 Open set + key
Networks Foundations Intermediate 7 questions
Graph TheoryMathematicsComputer Science

Matchings: Foundations

Seven foundations problems with complete solutions for matchings.

Published February 22, 2026 Open set + key
Networks Extension Intermediate 7 questions
Graph TheoryMathematicsComputer Science

Matchings: Extension

Seven extension problems with complete solutions for matchings.

Published February 24, 2026 Open set + key
Algorithms Foundations Beginner to intermediate 7 questions
AlgorithmsComputer Science

Shortest Paths: Foundations

Seven foundations problems with complete solutions for shortest paths.

Published February 28, 2026 Open set + key
Algorithms Extension Beginner to intermediate 7 questions
AlgorithmsComputer Science

Shortest Paths: Extension

Seven extension problems with complete solutions for shortest paths.

Published March 1, 2026 Open set + key
Probability Foundations Beginner to intermediate 7 questions
ProbabilityMathematics

Conditional Probability: Foundations

Seven foundations problems with complete solutions for conditional probability.

Published March 5, 2026 Open set + key
Probability Extension Beginner to intermediate 7 questions
ProbabilityMathematics

Conditional Probability: Extension

Seven extension problems with complete solutions for conditional probability.

Published March 7, 2026 Open set + key
Probability Foundations Intermediate 7 questions
ProbabilityMathematics

Bayes' Theorem: Foundations

Seven foundations problems with complete solutions for bayes' theorem.

Published March 9, 2026 Open set + key
Probability Extension Intermediate 7 questions
ProbabilityMathematics

Bayes' Theorem: Extension

Seven extension problems with complete solutions for bayes' theorem.

Published March 13, 2026 Open set + key
Probability Foundations Intermediate 7 questions
ProbabilityMathematics

Random Walks: Foundations

Seven foundations problems with complete solutions for random walks.

Published March 14, 2026 Open set + key
Probability Extension Intermediate 7 questions
ProbabilityMathematics

Random Walks: Extension

Seven extension problems with complete solutions for random walks.

Published March 17, 2026 Open set + key
Probability Foundations Intermediate 7 questions
ProbabilityMathematics

Markov Chains: Foundations

Seven foundations problems with complete solutions for markov chains.

Published March 18, 2026 Open set + key
Probability Extension Intermediate 7 questions
ProbabilityMathematics

Markov Chains: Extension

Seven extension problems with complete solutions for markov chains.

Published March 22, 2026 Open set + key
Algebra Foundations Intermediate 7 questions
AlgebraMathematics

Inequalities: Foundations

Seven foundations problems with complete solutions for inequalities.

Published March 24, 2026 Open set + key
Algebra Extension Intermediate 7 questions
AlgebraMathematics

Inequalities: Extension

Seven extension problems with complete solutions for inequalities.

Published March 27, 2026 Open set + key
Algebra Foundations Beginner to intermediate 7 questions
AlgebraMathematics

Sequences and Series: Foundations

Seven foundations problems with complete solutions for sequences and series.

Published March 28, 2026 Open set + key
Algebra Extension Beginner to intermediate 7 questions
AlgebraMathematics

Sequences and Series: Extension

Seven extension problems with complete solutions for sequences and series.

Published March 31, 2026 Open set + key
Algebra Foundations Intermediate 7 questions
AlgebraMathematics

Polynomial Roots: Foundations

Seven foundations problems with complete solutions for polynomial roots.

Published April 1, 2026 Open set + key
Algebra Extension Intermediate 7 questions
AlgebraMathematics

Polynomial Roots: Extension

Seven extension problems with complete solutions for polynomial roots.

Published April 6, 2026 Open set + key
Algebra Foundations Beginner to intermediate 7 questions
AlgebraMathematics

Complex Numbers: Foundations

Seven foundations problems with complete solutions for complex numbers.

Published April 11, 2026 Open set + key
Algebra Extension Beginner to intermediate 7 questions
AlgebraMathematics

Complex Numbers: Extension

Seven extension problems with complete solutions for complex numbers.

Published April 14, 2026 Open set + key
Linear Algebra Foundations Beginner to intermediate 7 questions
AlgebraMathematics

Vectors and Matrices: Foundations

Seven foundations problems with complete solutions for vectors and matrices.

Published April 17, 2026 Open set + key
Linear Algebra Extension Beginner to intermediate 7 questions
AlgebraMathematics

Vectors and Matrices: Extension

Seven extension problems with complete solutions for vectors and matrices.

Published April 20, 2026 Open set + key
Geometry Foundations Beginner friendly 7 questions
GeometryMathematics

Transformations and Symmetry: Foundations

Seven foundations problems with complete solutions for transformations and symmetry.

Published April 27, 2026 Open set + key
Geometry Extension Beginner friendly 7 questions
GeometryMathematics

Transformations and Symmetry: Extension

Seven extension problems with complete solutions for transformations and symmetry.

Published April 29, 2026 Open set + key
Decision Science Foundations Intermediate 7 questions
Game TheoryApplied Math

Game Theory: Foundations

Seven foundations problems with complete solutions for game theory.

Published May 1, 2026 Open set + key
Decision Science Extension Intermediate 7 questions
Game TheoryApplied Math

Game Theory: Extension

Seven extension problems with complete solutions for game theory.

Published May 5, 2026 Open set + key
Algorithms Foundations Intermediate 7 questions
AlgorithmsComputer Science

Greedy Algorithms: Foundations

Seven foundations problems with complete solutions for greedy algorithms.

Published May 9, 2026 Open set + key
Algorithms Extension Intermediate 7 questions
AlgorithmsComputer Science

Greedy Algorithms: Extension

Seven extension problems with complete solutions for greedy algorithms.

Published May 10, 2026 Open set + key
Discrete Math Foundations Intermediate 7 questions
Computer ScienceMathematics

Error-Correcting Codes: Foundations

Seven foundations problems with complete solutions for error-correcting codes.

Published May 13, 2026 Open set + key
Discrete Math Extension Intermediate 7 questions
Computer ScienceMathematics

Error-Correcting Codes: Extension

Seven extension problems with complete solutions for error-correcting codes.

Published May 17, 2026 Open set + key
Number Theory Foundations Intermediate 7 questions
Number TheoryMathematics

Introductory Cryptography: Foundations

Seven foundations problems with complete solutions for introductory cryptography.

Published May 19, 2026 Open set + key
Number Theory Extension Intermediate 7 questions
Number TheoryMathematics

Introductory Cryptography: Extension

Seven extension problems with complete solutions for introductory cryptography.

Published May 21, 2026 Open set + key
Applied Math Foundations Beginner to intermediate 7 questions
Applied MathMathematics

Mathematical Modeling: Foundations

Seven foundations problems with complete solutions for mathematical modeling.

Published May 25, 2026 Open set + key
Applied Math Extension Beginner to intermediate 7 questions
Applied MathMathematics

Mathematical Modeling: Extension

Seven extension problems with complete solutions for mathematical modeling.

Published May 29, 2026 Open set + key
Computer Science & AI Foundations Beginner to intermediate 7 questions
Computer ScienceMachine LearningEmbeddingsLinear Algebra

Embeddings and Representations: Foundations

Seven foundations problems with complete solutions for embeddings and representations.

Published July 16, 2026 Open set + key Read topic guide
Computer Science & AI Extension Beginner to intermediate 7 questions
Computer ScienceMachine LearningEmbeddingsLinear Algebra

Embeddings and Representations: Extension

Seven extension problems with complete solutions for embeddings and representations.

Published July 16, 2026 Open set + key Read topic guide
Computer Science & AI Foundations Beginner to intermediate 7 questions
Computer ScienceMachine LearningEmbeddingsLinear Algebra

Distance and Cosine Similarity: Foundations

Seven foundations problems with complete solutions for distance and cosine similarity.

Published July 10, 2026 Open set + key Read topic guide
Computer Science & AI Extension Beginner to intermediate 7 questions
Computer ScienceMachine LearningEmbeddingsLinear Algebra

Distance and Cosine Similarity: Extension

Seven extension problems with complete solutions for distance and cosine similarity.

Published July 10, 2026 Open set + key Read topic guide
Computer Science & AI Foundations Intermediate 7 questions
Computer ScienceMachine LearningEmbeddingsAlgorithms

Nearest Neighbors and Evaluation: Foundations

Seven foundations problems with complete solutions for nearest neighbors and evaluation.

Published July 22, 2026 Open set + key Read topic guide
Computer Science & AI Extension Intermediate 7 questions
Computer ScienceMachine LearningEmbeddingsAlgorithms

Nearest Neighbors and Evaluation: Extension

Seven extension problems with complete solutions for nearest neighbors and evaluation.

Published July 22, 2026 Open set + key Read topic guide
Computer Science & AI Foundations Intermediate 7 questions
Computer ScienceMachine LearningDimensionality ReductionLinear Algebra

PCA: Reducing Dimensions: Foundations

Seven foundations problems with complete solutions for pca: reducing dimensions.

Published August 3, 2026 Open set + key Read topic guide
Computer Science & AI Extension Intermediate 7 questions
Computer ScienceMachine LearningDimensionality ReductionLinear Algebra

PCA: Reducing Dimensions: Extension

Seven extension problems with complete solutions for pca: reducing dimensions.

Published August 3, 2026 Open set + key Read topic guide
Computer Science & AI Foundations Intermediate 7 questions
Computer ScienceMachine LearningNeural Networks

Neural Networks as Functions: Foundations

Seven foundations problems with complete solutions for neural networks as functions.

Published July 29, 2026 Open set + key Read topic guide
Computer Science & AI Extension Intermediate 7 questions
Computer ScienceMachine LearningNeural Networks

Neural Networks as Functions: Extension

Seven extension problems with complete solutions for neural networks as functions.

Published July 29, 2026 Open set + key Read topic guide
Computer Science & AI Foundations Intermediate to advanced 7 questions
Computer ScienceMachine LearningNeural NetworksOptimization

Training with Backpropagation: Foundations

Seven foundations problems with complete solutions for training with backpropagation.

Published August 8, 2026 Open set + key Read topic guide
Computer Science & AI Extension Intermediate to advanced 7 questions
Computer ScienceMachine LearningNeural NetworksOptimization

Training with Backpropagation: Extension

Seven extension problems with complete solutions for training with backpropagation.

Published August 8, 2026 Open set + key Read topic guide
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 01

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published June 3, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 02

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published June 8, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 03

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published June 10, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 04

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published June 11, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 05

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published June 15, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 06

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published June 20, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 07

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published June 25, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 08

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published July 1, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 09

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published July 4, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 10

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published July 12, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 11

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published July 14, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 12

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published July 19, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 13

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published July 22, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 14

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published July 24, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 15

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published July 27, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 16

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published July 29, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 17

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published July 30, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 18

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published August 6, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 19

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published August 7, 2026 Open set + key
Mixed Mixed review Mixed level 7 questions
MathematicsProblem Solving

Mixed Review 20

Seven cross-topic problems selected to practice method choice, explanation, and transfer.

Published August 9, 2026 Open set + key