Solution to: Big Numbers
Factorize the number 10000: 10000 = 2 × 2 × 2 × 2 × 5 × 5 × 5 × 5. Neither of the two numbers can contain the combination 2 × 5, because then the last digit of the number is definitely a zero. So one number has to be 2 × 2 × 2 × 2 = 16 and the other number 5 × 5 × 5 × 5 = 625.
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