What’s the difference between a two-digit number and its reverse?
- Choose a two-digit number, e.g., 20. Make a new number by reversing the digits, e.g., 02.
- Subtract the smaller number from the larger number, e.g., 20 - 02 = 18.
- Check your subtraction by adding your result, e.g., 18 + 02 = 20.
- Do you notice a pattern? If not, choose another two-digit number and go back to step 1.
On the basis of your findings, see if you can predict the difference between a two-digit number and its reverse.
For more of a challenge, investigate three-digit numbers.
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