Unit 5, Lesson 21
Multiply More Decimals
Grade 5
Warm-up
Estimation Exploration: Central Park
Central Park is a large park in Manhattan. It is about 3.85 kilometers long and 0.79 kilometer wide. What is the approximate area of Central Park?
Record an estimate that is:
| too low | about right | too high |
|---|---|---|
Student Section Summary
We learned different strategies for multiplying with decimals.
We used place value relationships to reason about the multiplication.
Example:
We used properties of operations to break up the multiplication.
Example:
We also used diagrams to represent the multiplication.
Example: This diagram shows 17 groups of 3 hundredths is 51 hundredths, so
Two diagrams. Each squares. Length and width, 1. Each partitioned into 10 rows of 10 of the same size squares. On left, 30 squares shaded. On right, 21 squares shaded.