Find the missing number that makes both sides equal.
92 + 308 = ? + 300
Show the worked answer
Answer: C, 100
How to work it out
- The left side is 92 + 308 = 400.
- So ? + 300 = 400, and ? = 400 − 300 = 100.
- A quicker way: 300 is 8 less than 308, so ? must be 8 more than 92.
Why the other options are wrong
- A (400): This is the total of the left side. The right side already has 300 in it, so the missing number is smaller.
- B (8): This is only the difference between 308 and 300.
- D (84): The right side's number is 8 smaller, so the missing number must be 8 bigger, not smaller.
- E (92): This assumes 308 and 300 are the same; they differ by 8.