Week 12TuesdayStrategy: Group Friendly Numbers
1Warm-up: ±10 Mental Math

2-min Fluency Warm-up — Mental math. Go fast!

53 + 10 =

68 − 10 =

91 + 10 =

74 − 10 =

2Strategy: Friendly Numbers

Pro Strategy: Group "Friendly Numbers"

Look for two numbers that add up nicely (to 10, 20, 30...).

18 + 32 + 25

18 + 32 = 50 ← nice round number!

50 + 25 = 75

43 + 7 + 29

43 + 7 = 50 ← nice round number!

50 + 29 = 79

3Find the Friendly Pair

Circle the two numbers that are easiest to add first, then solve.

25 + 15 + 38 =

I added ______ and ______ first because

6 + 34 + 22 =

I added ______ and ______ first because

40 + 28 + 12 =

I added ______ and ______ first because

53 + 7 + 19 =

I added ______ and ______ first because

4Word Problems

Look for friendly numbers in these problems.

At lunch, 18 kids ate chicken nuggets, 12 kids ate sandwiches, and 27 kids ate pizza. How many kids ate lunch?

Draw or write your thinking:

kids

The garden has 24 red flowers, 6 yellow flowers, and 35 blue flowers. How many flowers are in the garden?

Draw or write your thinking:

flowers

Two Ways! Solve 16 + 24 + 8 two different ways. Pick a different pair to add first each time.

Way 1: I added + first. Total:

Way 2 (another way): I added + first. Total:

Did you get the same total both ways? Why?

5Challenge: Make 100

Challenge: Can you make 100?

Fill in the blanks so all three numbers add up to 100. There are MANY answers!

+ + = 100

Show your work: