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Number Theory

Level 15 / build-up

GCD mastery (<= 500)

3 visual steps / Euclidean GCD

1. Euclid step

GCD(420, 315)1. Euclid stepReplace the pair with a remainder.1420 = 315 + 1052315 = 105 x 33GCD = 105
Replace the pair with a remainder.

Replace the pair with a remainder.

2. Repeat

GCD(420, 315)2. RepeatContinue until the remainder stops.1420 = 315 + 1052315 = 105 x 33GCD = 105
Continue until the remainder stops.

Continue until the remainder stops.

3. Last divisor

GCD(420, 315)3. Last divisorThe last divisor is the GCD.1420 = 315 + 1052315 = 105 x 33GCD = 105
The last divisor is the GCD.

The last divisor is the GCD.

Practice Level 15

Use the visible move, then type only when the answer is clear.

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