Add Three Numbers!
Kit is at the sea. She picks up lots of shells! Can we add up all of them?
1st Grade MathStep 1: Add Two Numbers First
Use blocks to model Kit's shells: 3 blocks and 2 blocks. Add 3 + 2.
3 + 2 = 5.
Count on
from 3: say 4, then 5!
Step 2: Add the Last Number
Use 4 more blocks to model the last shells. Now add 5 + 4.
5 + 4 = 9. The
sum
of all the shells is 9!
Let's Remember
How to Add 3 Numbers
Step 1: Add two of the numbers.
Step 2: Add the last number.
You can solve it two steps at a time!
Step 2: Add the last number.
You can solve it two steps at a time!
3 + 2 + 4 = 9
Solve It!
2 + 5 + 1 = ?
2 + 5 = 7. Then 7 + 1 = 8. The sum is 8!
Word Problem
Meg has 5 red hats and 3 pink hats. She also has 2 green hats.
How many hats in all?
5 + 3 = 8. Then 8 + 2 = 10. Meg has 10 hats!
What Goes in the Blank?
4 + ? + 3 = 10
4 + 3 = 7. Then 7 + 3 = 10. The blank is 3!
At the Pond
Dot is at the pond. She sees 7 ducks, 2 frogs, and 5 fish.
How many in all?
7 + 2 = 9. Then 9 + 5 = 14. Dot sees 14 in all!
Solve It!
6 + 6 + 4 = ?
See 6 and 6? That is a doubles fact!
6 + 6 = 12 is a doubles fact. Then 12 + 4 = 16!
Challenge!
Kit has 7 shells. Meg has 5 shells and Dot has 3 shells.
How many shells in all?
Look for a ten! 7 + 3 = 10. Then 10 + 5 = 15. Pick two numbers that
make ten first!
You Think!
What three sets of things can you add up at home?
Great Work!
0/7
correct
add
solve
sum
count on
doubles