How to Regroup Ones into Tens

In the last lesson, we learned how to add two-digit numbers using column form.

What's 11 + 18?

Start by writing the addition in column form, like this:

Now, add the Ones digits.

Then, add the Tens place digits:

So, 11 + 18 = 29.

Can you do that in your head? Try it.

Now, something cool happens when we add even bigger numbers. Let's take a look.

Solve 13 + 18

Start by writing the equation in column form:

What's 8 + 3? 11. But you can't write two digits in the Ones place. 

Each column can only have one digit.

That's when you regroup.

      When one column adds up to more than 10, you regroup 10 Ones into 1 Tens.

This is also called "carrying the 1 over":

Tip: Don't put the carry over in the answer area at the bottom of the column. Write it at the top.

After we carry the 1, we add all the Tens place digits, including the carry.

So, 13 + 18 = 31 🎉

Congratulations, you learned how to regroup, or "carry the 1". 

Now, try the practice to become a regrouping master. You'll use this skill a lot.

Believe in yourself. You can learn anything.