Lesson 5: Practice Problems

Problem 1

Select all the expressions that equal $\frac{3.15}{0.45}$ .

$(3.15) \cdot (0.45)$
$(3.15) \div (0.45)$
$(3.15) \cdot \frac{1}{0.45}$
$(3.15) \div \frac{45}{100}$
$(3.15) \cdot \frac{100}{45}$
$\frac{0.45}{3.15}$

Problem 2

Which expressions are solutions to the equation $\frac{3}{4} x = 15$ ? Select all that apply.

$\frac{15}{\frac{3}{4}}$
$\frac{15}{\frac{4}{3}}$
$\frac{4}{3} \cdot 15$
$\frac{3}{4} \cdot 15$
$15 \div \frac{3}{4}$

Problem 3

Solve each equation.

$4 a = 32$
$4 = 32 b$
$10 c = 26$
$26 = 100 d$

Problem 4

For each equation, write a story problem represented by the equation. For each equation, state what quantity $x$ represents. If you get stuck, consider drawing a diagram.

$\frac{3}{4} + x = 2$
$1.5 x = 6$

Problem 5 From Unit 3 Lesson 13

Write as many mathematical expressions or equations as you can about the image. Include a fraction, a decimal number, or a percentage in each.

A fundraiser thermometer labeled "Fundraiser, our goal, 2 hundred 50 thousand dollars." The numbers 50 thousand through 2 hundred 50 thousand, in increments of 50 thousand dollars, are indicated. There are 4 evenly spaced tick marks between each indicated dollar value. Starting from the bottom, the thermometer is shaded to the first tick mark above 1 hundred thousand dollars.

Problem 6 From Unit 3 Lesson 12

In a lilac paint mixture, 40% of the mixture is white paint, 20% is blue, and the rest is red. There are 4 cups of blue paint used in a batch of lilac paint. If you get stuck, consider using a tape diagram.

How many cups of white paint are used?
How many cups of red paint are used?
How many cups of lilac paint will this batch yield?

Problem 7 From Unit 1 Lesson 9

Triangle P has a base of 12 inches and a corresponding height of 8 inches. Triangle Q has a base of 15 inches and a corresponding height of 6.5 inches. Which triangle has a greater area? Show your reasoning.