Ella's Math Library

Every question becomes a lesson. Find it later by date, key idea, formula, or the words you remember.

4 lessons3 categoriesAMC 8 → AMC 10

Question timeline

4 lessons

Counting Without Missing or Repeating

Learn when to add, multiply, arrange, choose, subtract bad cases, or build a recurrence—from genuine AMC 8 patterns.

CountingPermutationsCombinationsAMC 8AMC 10
Open lesson

Fibonacci Numbers and the Golden Ratio

Why does the equation 1 = 1/a − a produce 0.618, and what does self-similarity really mean?

SequencesGolden ratioQuadraticsAMC 8AMC 10
Open lesson

Divide, Multiply, Subtract, Bring Down

Divide polynomials in x while treating y as a coefficient, and check the remainder quickly.

Polynomial divisionRemainder theoremAMC 10
Open lesson

Sliding Lines

Translate points and lines, derive g(x) = f(x − h) + k, and see why slope stays unchanged.

Linear functionsGraph transformationsAMC 8
Open lesson