Column addition is a way of adding numbers together. It's helpful when you're adding two-digit or three-digit ... 3 tens + 2 tens + 1 ten (from the regrouping) = 6 tens Image caption, That is ...

Complete this quiz to understand how to add up to 4-digit ... addition. Let's look at another question. Start from the ones column: 3 + 9 = 12. This needs regrouping, so 12 can be regrouped to 10 + 2.