# Video: KS2-M16 • Paper 1 • Question 18

122,456 − 11,999 = ＿.

03:25

### Video Transcript

122456 subtract 11999 equals what?

11999 is one less than 12000. So if we add one, we can round this number to 12000. We also need to add one to 122456 to make the difference between these two numbers the same. Now, we can calculate 122457 subtract 12000. These digits represent the hundreds, tens, and ones. 12000 has no hundreds, no tens, and no ones. So there’s nothing to subtract in these three columns. So 457 doesn’t change.

In this column, we need to subtract two thousands from 2000 which gives us zero. Next, we need to subtract 10000 from 20000 which is 10000. So we write a one in the 10000 column. In the hundred thousands column, there’s nothing to subtract from one. One take away nothing is one. So 122456 subtract 11999 equals 110457.

Another way to find the answer would be to round 11999 to 12000 by adding one, and then subtract 12000 from 122456. You may have noticed we haven’t added the extra one to 122456. We can do that at the end of our calculation. 122456 subtract 12000 is equal to 110456. Now, we need to add a one to our answer. 110456 plus one is 110457.

We found our answer in two different ways. First, we rounded 11999 to the nearest thousand by adding one. Then we added one to 122456 to make sure the difference between these two numbers was still the same. And then we subtracted our new numbers.

And the second way we found our answer was to round 11999 to the nearest thousand. Then we subtracted the two numbers. And then we added one to the answer. 122456 subtract 11999 is 110457.