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Adding a 1-digit Number to a 2-digit Number (with regrouping)
We can find the sum of a one-digit and a two-digit number by regrouping.
For example: Let's find the sum of 11 and 9.
To find the sum of the numbers:
First, add the ones and remember to regroup.
1 | ||
1 | 1 | |
|
9 |
0 |
Now, add the tens.
1 | ||
1 | 1 | |
|
9 |
2 | 0 |
The sum of the given numbers is 20.