A. Decimal expansions and repeating fractions
Verify these decimal expansions:
1/3 = 0.(3)
1/6 = 0.1(6)
7/30 = 0.2(3)
7/11 = 0.(63)
Find the 100th digit after the decimal point in the expansion of 1/7.
Division by strings of 9s; purely periodic fractions:
Compute by long division: 1 ÷ 9; 1 ÷ 99; 1 ÷ 9,999.
Prove the general rule: 1/(99…9) = 0,(00…01), where the denominator has n nines and the repeating block has length n with (n−1) zeros followed by
Sign in or create an account to reveal answers, view the solution, and save your progress. Create a free account to unlock practice and keep track of your work.
One puzzle per day. Cryptarithm, Magic Square, Summit. No sign-up required to play.
Play daily puzzle →Interactive problems and curated lessons—water pouring, magic squares, knight's tour, and more.
Browse library →See how you rank. Top solvers by problems solved correctly. Sign in to climb the ranks.
View leaderboard →