Lesson 8: Practice Problems

Problem 1

Here are an unfinished calculation of $(0.54) \cdot (3.8)$ and a 0.54-by-3.8 rectangle.

A unfinished vertical multiplication problem for 0.54 times 3.8

Which part of the rectangle has an area of 0.432? Which part of the rectangle has an area of 1.62? Show your reasoning.
What is $(0.54) \cdot (3.8)$ ?

Problem 2

Explain how the product of 3 and 65 could be used to find $(0.03) \cdot (0.65)$ .

Problem 3

Use vertical calculation to find each product.

$(5.4) \cdot (2.4)$
$(1.67) \cdot (3.5)$

Problem 4

A pound of blueberries costs $3.98 and a pound of clementines costs $2.49. What is the combined cost of 0.6 pound of blueberries and 1.8 pounds of clementines? Round your answer to the nearest cent.

Problem 5 From Unit 5 Lesson 3

Complete the calculations so that each shows the correct sum or difference.

Problem 6 From Unit 5 Lesson 4

Which has a greater value: $7.4 - 0.0022$ or $7.39 - 0.0012$ ? Show your reasoning.

Problem 7 From Unit 2 Lesson 12

Andre is planting saplings (baby trees). It takes him 30 minutes to plant 3 saplings. If each sapling takes the same amount of time to plant, how long will it take Andre to plant 14 saplings? If you get stuck, consider using the table.

number of saplings	time in minutes
$3$	$30$
$1$
$14$