# Lesson 2

Truth and Equations

Let's use equations to represent stories and see what it means to solve equations.

### Problem 1

Select **all** the true equations.

\(5 + 0 = 0\)

\(15 \boldcdot 0 = 0\)

\(1.4 + 2.7 = 4.1\)

\(\frac{2}{3} \boldcdot \frac{5}{9} = \frac{7}{12}\)

\(4 \frac{2}{3}=5 - \frac{1}{3}\)

### Problem 2

Mai's water bottle had 24 ounces in it. After she drank \(x\) ounces of water, there were 10 ounces left. Select **all** the equations that represent this situation.

\(24 \div 10 = x\)

\(24 +10 = x\)

\(24 - 10 = x\)

\(x + 10 = 24\)

\(10x = 24\)

### Problem 3

Priya has 5 pencils, each \(x\) inches in length. When she lines up the pencils end to end, they measure 34.5 inches. Select **all** the equations that represent this situation.

\(5 + x = 34.5\)

\(5x = 34.5\)

\(34.5 \div 5 = x\)

\(34.5 - 5 = x\)

\(x = (34.5) \boldcdot 5\)

### Problem 4

Match each equation with a solution from the list of values.

### Problem 5

The daily recommended allowance of vitamin C for a sixth grader is 45 mg. 1 orange has about 75% of the recommended daily allowance of vitamin C. How many milligrams are in 1 orange? If you get stuck, consider using the double number line.

### Problem 6

There are 90 kids in the band. 20% of the kids own their own instruments, and the rest rent them.

- How many kids own their own instruments?
- How many kids rent instruments?
- What percentage of kids rent their instruments?

### Problem 7

Find each product.

- \((0.25) \boldcdot (1.4)\)
- \((0.061) \boldcdot (0.43)\)
- \((1.017) \boldcdot (0.072)\)
- \((5.226) \boldcdot (0.037)\)