Multiplying a repeating 1's number by 25

Follow the following Steps:

1. Choose a repeating 1's number (111, etc.)
2. Multiply it by 25
3. The product is:
   - first digit is 2
   - next digits are 7's - one fewer than repeating 1's in the original number
   - last digit is 5.

   Example:1

1. If the first number is 11111:
2. Multiply by 25. The product is:
   first digit is 2: 2
   next digits are 7's, one fewer than 1's: 7777
   last digit is 5: 5
3. So 11111 × 25 = 277775.   

Example:2

1. If the first number is 11111111:
2. Multiply by 25. The product is:
   first digit is 2: 2
   next digits are 7's, one fewer than 1's: 7777777
   last digit is 5: 5
3. So 11111111 × 25 = 277777775