Units Digits & Cycles
The last digits of repeated powers often form periodic residue cycles, so a huge exponent can be replaced by its position in a short cycle.
What you'll learn
- Generate and verify a units-digit cycle by repeated multiplication modulo 10.
- Reduce a large exponent to a correctly indexed cycle position.
- Handle remainder zero as the final slot of a one-indexed power cycle.
- Track and combine separate cycles in sums of powers.
Before you start
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