Multiplying a repeating 9's number by 88
Follow the following Steps:
- Choose a repeating 9's number (at least three digits long -- 999, etc.)
- Multiply it by 88
- The product is:
- the first two digits are 87
- the next digits are repeating 9's (two fewer than repeating 9's in the original number)
- the last two digits are 12
- If the first number is 8888:
- Multiply by 88. The product is:
- the first two digits are 87: 87.
- the next digits are repeating 9's (two fewer than repeating 9's in the original number): 99.
- the last two digits are 12: 12. - So 9999 × 88 = 879912.
- If the first number is 999999:
- Multiply by 88. The product is:
- the first two digits are 87: 87.
- the next digits are repeating 9's (two fewer than repeating 9's in the original number): 9999.
- the last two digits are 12: 12. - So 999999 × 88 = 87999912