Add and Regroup

Lesson Plan - Get It!

Audio:

• What happens when you have more than ten ones in the ones place?

When you are adding, you cannot have more than 9 in any column, so you have to regroup. Regrouping means renaming a group of ten or changing the ten ones into one ten.

Look at the example below of 17 + 13.

Start adding the ones column: 7 + 3 = 10

However, we cannot put a two-digit number in a column.

Ten ones is the same as one ten. Think of counting coins. When you have ten pennies, you can exchange them for one dime, which is worth ten cents.

When adding numbers, any amount over nine needs to be regrouped.

Watch some examples of how regrouping and place value are related with Addition with Regrouping (Math Playground LLC).

After the video, explain in your own words how you know when you need to regroup by looking at a number.

Hopefully, you said that regrouping occurs when an addition problem gives you a sum that is 10 or more!

Addition with regrouping happens in calculations involving story problems or money as well, like in the following example:

Jimmy has $45 in his pocket. He earns $26 while mowing his grandma's lawn. How much money does Jimmy have now?

• Which of the following problems would require you to use regrouping?

Look at the problem and determine whether grouping would be necessary or not without actually solving the problem. Click on "Yes" or "No":

• How did you determine which problems needed regrouping?

You are ready to practice addition with regrouping with interactive activities and games.

So, continue on to the Got It? section and practice problems with an interactive and addition game!