Let’s look at another example. This one is a little more difficult, 683 take away 426. In the Units column, 3 take away 6, we can’t do that, so we need to trade from the 10s column. We give a 10 to the number at the top of the Units column, and we add on a 10 in the 10s column to the bottom number. In this case, the number 2 will become 3, so in the Units column we now have 13 take away 6. Are you thinking about the answer? That’s right, it’s seven. Put the seven in the Units column.

In the 10s column, we have 8 take away 3, and the answer to that is 5. Put the 5 in the 10s column. In the 100s column, we have 6 take away 4, and the answer to that is 2. Put the 2 in the 100s column. The answer to our problem is 257.