Lesson 07: Using Diagrams to Represent Multiplication | Unit 5: Arithmetic in Base Ten

Multiple Choice

For the given rectangle partitioned into four smaller rectangles, which sub-rectangle has an area, in square units, that matches the expression $$(0.4) \cdot 2$$ ?

• None of the sub-rectangles match the area of (0.4) * 2.
• Sub-rectangle C has an area of 0.6 square units.
• Sub-rectangle B has an area of 0.8 square units.
• Sub-rectangle A has an area of 1.2 square units.

Multiple Choice

For the given rectangle partitioned into four smaller rectangles, which sub-rectangle has an area, in square units, that matches the expression $$(0.4) \cdot (0.6)$$ ?

• Sub-rectangle A (width 0.4 and height 0.6)
• Sub-rectangle B (width 0.5 and height 0.4)
• Sub-rectangle C (width 0.3 and height 0.8)
• Sub-rectangle D (width 1.0 and height 1.0)

Multiple Choice

For the given rectangle partitioned into four smaller rectangles, which sub-rectangle has an area, in square units, that matches the expression $$3 \cdot 2$$ ?

• A
• B
• C
• D

Multiple Choice

What are the areas of sub-rectangles A and B in the area diagram that represents $$(3.1) \cdot (1.4)$$ ?

• A: 3.0, B: 1.5
• A: 3.1, B: 1.24
• A: 3.1, B: 1.5
• A: 2.5, B: 1.5

Multiple Choice

What is the area of the 3.1 by 1.4 rectangle in the area diagram?

• 4.0
• 4.34
• 5.0
• 3.5

Multiple Choice

What is the result of $$(0.36)\cdot(0.53)$$ using an area diagram?

• 0.1806
• 0.1908
• 0.2000
• 0.2500

Open Ended

Find the product of $$(2.5) \cdot (1.4)$$ . Show your reasoning.

Open Ended

Find the product of (0.64) * (0.81). Show your reasoning.

Multiple Choice

Suppose one ounce of craft paint will cover 1.2 square feet. How many square feet would 14.25 ounces of craft paint cover?

• 0.171 square foot

• 1.71 square feet

• 17.1 square feet

• 171 square feet

Open Ended

Jada explains how she finds $$15 \cdot 23$$ : “I know that ten 23s is 230, so five 23s will be half of 230, which is 115. 15 is 10 plus 5, so $$15 \cdot 23$$ is 230 plus 115, which is 345.” Do you agree with Jada? Explain your reasoning.