# Place Value Strategies

Videos and solutions to help Grade 3 students learn how to use place value strategies and the associative property n × (m × 10) = (n × m) × 10 (where n and m are less than 10) to multiply by multiples of 10.

Common Core Standards: 3.OA.5, 3.OA.8, 3.OA.9, 3.NBT.3, 3.OA.1

Related Topics:
Lesson Plans and Worksheets for Grade 3

Lesson Plans and Worksheets for all Grades

More Lessons for Grade 3

Common Core For Grade 3

New York State Common Core Math Module 3, Grade 3, Lesson 20

Application Problem

Model 3 × 4 on a place value chart. Then explain how the array can help you solve 30 × 4.

Note: This problem reviews multiplying by multiples of 10 from Lesson 19. In today’s Concept Development, students will build on their understanding from Lesson 19 to multiply by multiples of 10 using the associative property.

Lesson 20 Homework

1. Use the chart to complete the equations. Then solve.
a. (2 × 5) × 10
= (10 ones) × 10
= _______
b. 2 × (5 × 10)
= 2 × (5 tens)
= _______

2. Solve. Place ( ) in (c) and (d) as needed to find the related fact.
a. 3 × 20 = 3 × (2 × 10)
= (3 × 2) × 10
= 6 × 10
= ______
b. 3 × 30 = 3 × (3 × 10)
= (3 × 3) × 10
= ______ × 10
= ______
c. 3 × 40 = 3 × (4 × 10)
= 3 × 4 × 10
= ______ × 10
= ______
d. 3 × 50 = 3 × 5 × 10
= 3 × 5 × 10
= ______ × 10
= ______

3. Danny solves 5 × 20 by thinking about 10 × 10. Explain his strategy.
Lesson 20 Homework

Multiply by Multiples of 10 Using the Place Value Chart

2 c) 3 × 40 = 3 × (4 × 10)

= 3 × 4 × 10

= ______ × 10
= ________
d) 3 × 50 = 3 × 5 × 10

= 3 × 5 × 10

= ______ × 10
= _______

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