Section C: Practice Problems Add Within 20

Section Summary

Details

We saw that making a ten could help when we add 3 numbers together.

$4 + 8 + 6 = 10 + 8 = 18$

Double ten frame. 4 red counters. 6 yellow counters. 8 blue counters.

We saw that making a ten could also help when we add 2 numbers together.

$4 + 8 = 4 + 6 + 2 = 10 + 2 = 12$

Double ten frame. Red, 4 counters. Yellow, 8 counters.

Problem 1 (Lesson 15)

There are 5 bananas, 6 oranges, and 4 apples in a bowl.
How many pieces of fruit are in the bowl?
Show your thinking using objects, drawings, numbers, or words.

Equation:

Problem 2 (Lesson 16)

Select 3 expressions that are equal to $10 + 8$ .

$5 + 5 + 8$
$9 + 7 + 3$
$1 + 9 + 9$
$3 + 8 + 7$
$8 + 4 + 6$

Problem 3 (Lesson 17)

Find the value of each sum.
Show your thinking using drawings, numbers, or words.

$9 + 6$
$4 + 9$
$7 + 5$
$8 + 4$

Problem 4 (Lesson 18)

Select 3 expressions that have the same value as 10 + 3.

$9 + 4$
$2 + 12$
$5 + 8$
$7 + 6$
$5 + 9$

Problem 5 (Lesson 19)

Find the value of each sum.
Show your thinking using drawings, numbers, or words.

$3 + 9$
$6 + 5$
$8 + 7$

Problem 6 (Lesson 20)

Jada has 6 connecting cubes.
Han has 8 connecting cubes.
Lin has 5 connecting cubes.
How many cubes do Jada, Han, and Lin have all together?
Show your thinking using drawings, numbers, or words.

Problem 7 (Exploration)

Tyler started counting up from 3.
Mai started counting back from 15.
Which number do Tyler and Mai say at the same time?
Show your thinking using drawings, numbers, or words.
Clare started counting up from 1.
Andre started counting back from 20.
Do Andre and Clare say the same number at the same time?
Show your thinking using drawings, numbers, or words.

Problem 8 (Exploration)

Write an addition story problem using 3 numbers from the list:
- 3
- 5
- 7
- 4
- 9
- 6
Solve your story problem.
Write an equation that matches the story problem.
Equation:
Exchange your story with a classmate and solve each other’s problem.