# Video: KS2-M16 • Paper 1 • Question 12

50 × 70 = ＿.

02:33

### Video Transcript

50 multiplied by 70 equals what?

Both of these numbers are multiples of 10. If we divide them by 10, we’re left with a much easier calculation, five times seven. Five-sevenths of 35. We could use this fact to help us calculate 50 times seven. 50 is 10 times greater than five. And 350 is 10 times greater than 35. Five times seven is 35. 50 times seven is 350. We can use this fact to help us find 50 times 70. 70 is 10 times greater than seven. And 3500 is 10 times greater than 350. So 50 times 70 is 3500.

Another way we could calculate 50 times 70 is to use another known fact. We know that 50 is half of 100. So we can double 50 to find 100 times 70, which is 7000. Now that we know 100 times 70 is 7000, we can use this to help us find 50 times 70. Since 50 is half of 100, 50 times 70 will be half of 7000. So we get the same answer 3500.

50 multiplied by 70 equals 3500. We used two different strategies to help find the answer. First, we found five times seven and used this to help us find 50 times seven. And then used that to find 50 times 70. The second way we found the answer was to first find 100 times 70 and then halve the answer to find 50 times 70. Both methods gave us the correct answer of 3500.