# Video: KS2-M18 • Paper 1 • Question 6

5 × 4 × 10 = ＿.

01:38

### Video Transcript

Five multiplied by four multiplied by 10 equals what?

In this question, we’re being asked to multiply three numbers together. Remember, when we multiply numbers, we can multiply them in any order. And it will give us the same result. So we can choose the order that we multiply these numbers together. Which way is going to be the quickest?

Well, multiplying any number by 10 is quick to work out. So one efficient method of finding the answer is to start by multiplying five by four and then multiply that answer by 10. Five multiplied by four equals 20. And so our calculation becomes 20 multiplied by 10, which equals 200.

Another method we could use is to spot that five multiplied by 10 gives us 50. And 50 is also quite quick to multiply. Anyway, what we’re doing is juggling around the order of the numbers. But remember, this won’t affect the answer.

Start by multiplying five by 10, which gives us an answer of 50. Then, all we have to do to find the answer is to multiply 50 by four, which is quite quick to do. Four lots of 50 equals 200. So whichever way we choose to multiply the numbers, we should be able to work out the answer mentally and not need to write anything down.

Five multiplied by four multiplied by 10 equals 200.