1. Addition and Subtraction in Context

2. How do we know when to use addition or subtraction
How do we know when to use addition or subtraction? Key words give us hints. They tell us if we need to add or subtract!
Addition Key Words
Subtraction Key Words

5. Miss K has 12 cousins in all. Five of them are boys. How many are girls?
What are some strategies we can use to figure this out?
Look for key words to figure out if you need to add or subtract
Draw a simple picture or diagram
How many steps do we need to take to solve this problem?
Or… CUBES!

6. Write these in your math notebook!

7. Miss K has 12 cousins in all. Five of them are boys. How many are girls?

8. Miss K has 12 cousins in all. Five of them are boys. How many are girls?

9. Miss K has 12 cousins in all. Five of them are boys. How many are girls?

10. Miss K has 12 cousins in all. Five of them are boys. How many are girls?
Make sure the picture is simple!

11. Miss K has 12 cousins in all. Five of them are boys. How many are girls?

12. Use the C.U.B.E.S. strategy to solve:
A garden has 103 flowers in it. Forty-nine of them are roses, 28 of them are mums, and the rest are tulips. How many flowers in the garden are tulips?
103 Flowers
Roses
Mums
Tulips

13. Another way to check our answer…
If we start with 103 flowers,
103
We can subtract the roses,
103 – 49 = 54
Then we can subtract the mums from that,
54 – 28 = 26
And the difference is the number of tulips:
26 tulips

14. Let’s practice finding the missing addend:
_____ = _____ = _____ = 492

15. Use the C.U.B.E.S. strategy to solve:
A factory has 3,478 bags of candy. The factory shipped out 239 bags of candy to a grocery store in New York City. The factory shipped out 312 bags to a grocery store in Boston. How many bags of candy were left at the factory?
Am I supposed to draw over 3,000 bags of candy?