# Video: Using a Blank Number Line to Subtract within 1000

615 − 424 = ＿

02:18

### Video Transcript

615 subtract 424 equals what?

In this question, we’re given a number line to help us subtract. We need to start at 615 and subtract 424. To help us subtract, we can partition the number 424 into hundreds, tens, and ones. Then, we can subtract each part from 615. 424 has four ones, two tens, which is worth 20, and four hundreds, which is worth 400.

Let’s start by subtracting the hundreds, 615 take away 400. Well, we know that six take away four is two, so sex hundreds take away 400 will be 200. 615 take away 400 is 215. Next, we need to take away our tens. We need to take away two tens, which is worth 20. 215 take away 10 is 205, take away another 10 is 195.

Our final step is to subtract the ones. We need to take away four ones. 195 subtract four is 191. We had to subtract 424 from 615. We partitioned 424 into hundreds, tens, and ones. Then, we took away the hundreds, the tens, and the ones from 615. 615 subtract 424 equals 191.