Missing factors
The question
11 × ? = 55
11×?=55
11×?=55
11, 22, 33, 44, 55=5 × 11
11×5=55
- The gap is not at the end this time — the ANSWER is already there. What is missing is one of the two numbers going in, so the sum cannot just be worked left to right.
- How many 11s make 55? Count them: 11, 22, 33, 44, 55 — that is 5 of them.
- Put it back in to be sure: 11 × 5 = 55. It holds, so the missing number is 5.
How it works.
- 01
The gap is not at the end this time — the ANSWER is already there. What is missing is one of the two numbers going in, so the sum cannot just be worked left to right.
- 02
How many 11s make 55? Count them: 11, 22, 33, 44, 55 — that is 5 of them.
- 03
Put it back in to be sure: 11 × 5 = 55. It holds, so the missing number is 5.