1. Double-Digit Addition Strategies
= ??? 63
+25 ??
Double-Digit Addition Strategies 79
+ 25 ??
= ???

2. Add the digits in the ones and tens places
How do we solve this equation? 23 + 41 =
Strategy 1
Use base-ten blocks
Strategy 2
Add the digits in the ones and tens places

3. Strategy 1
Use base-ten blocks.

4. First, we need to set the equation up in a way that is easier to solve.23 41 + =

5. Make sure that the numbers line up in the tens and ones places.
2 3
4 1 +

6. First, we’ll solve for the ones.
Tens
Ones
2 3
Here are three ones.
4 1 +
Here is one ones. 4
How many ones all together?

7. Next, we’ll solve for the tens.
Ones
2 3
Here are two tens (20).
4 1 +
Here are four tens (40). 6 4
How many tens all together?

8. Now we know the sum (answer) of twenty-three plus forty-one equals 64!23 + 41 = 64

9. Add the digits in the ones and tens places.
Strategy 2
Add the digits in the ones and tens places.

10. First, we need to set the equation up in a way that is easier to solve.23 41 + =

11. Make sure that the numbers line up in the tens and ones places.
2 3
4 1 +

12. Now add the digits in the Ones place.
Tens
Ones
2 3 3 +
= 4
4 1 1 + 4

13. Next, add the digits in the tens place.
Ones + =6 2
2 3 3 4
4 1 1 + 6 4

14. Now we know the sum (answer) of twenty-three plus forty-one equals 64!23 + 41 = 64