Codes, Cryptography & BlockchainModular Arithmetic
Clock Math
Huge numbers reveal their endings when you count like a clock
7 to the power of 100 has 85 digits. Could you find its last one in your head, faster than a calculator?
You'll find out
- What clocks have to do with numbers
- How to see a huge number's last digit
- Where this math guards your secrets
Why it matters
Wrap-around counting runs your calendar and your browser's padlock. One trick tames numbers too big to write.
Play this lesson
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