# Math in Focus Grade 7 Chapter 2 Answer Key Rational Number Operations

Go through the Math in Focus Grade 7 Workbook Answer Key Chapter 2 Rational Number Operations to finish your assignments.

## Math in Focus Grade 7 Course 2 A Chapter 2 Answer Key Rational Number Operations

### Math in Focus Grade 7 Chapter 2 Quick Check Answer Key

Complete each ? with > or <.

Question 1.
-3 ? 5
-3 < 5
Explanation:
Compare the above two numbers. The number -3 is less than 5.

Question 2.
-7 ? -12
-7 > -12
Explanation:
Compare the above two numbers. The number -7 is greater than -12.

Question 3.
10 ? -16
10 > -16
Explanation:
Compare the above two numbers. The number 10 is greater than -16.

Question 4.
-28 ? 0
-28 < 0
Explanation:
Compare the above two numbers. The number -28 is less than 0.

Question 5.
$$\frac{1}{2}$$ ? $$\frac{3}{4}$$
1/2 < 3/4
Explanation:
Compare above two fractions. The fraction 1/2 is less than 3/4.

Question 6.
-1$$\frac{1}{4}$$ ? 2$$\frac{2}{3}$$
The mixed fraction -1(1/4) in fraction form as -5/4.
The mixed fraction 2(2/3) in fraction form as 8/3.
-1(1/4) < 2(2/3)
Explanation:
Compare above two mixed fractions. The mixed fraction -1(1/4) is less than 2(2/3).

Question 7.
0.15 ? 0.13
0.15 > 0.13
Explanation:
Compare the above decimal numbers. The decimal number 0.15 is greater than 0.13.

Question 8.
-1.23 ? -1.25
-1.23 > -1.25
Explanation:
Compare the above decimal numbers. The decimal number -1.23 is greater than -1.25.

Evaluate each expression.

Question 9.
75 – (18 + 2) ∙ 3
75 – (18 + 2) ∙ 3 Given
= 75 – 20 ∙ 3 Perform operation in parentheses
= 75 – 60 Multiply
= 15 subtract

Question 10.
15 ∙ (40 ÷ 8) + 72
15 ∙ (40 ÷ 8) + 72 Given
= 15 ∙ 5 + 72 Perform operation in parentheses
= 75 + 72 Multiply
= 147

Express each improper fraction as a mixed number.

Question 11.
$$\frac{12}{17}$$

Question 12.
$$\frac{19}{3}$$
19/3 = 6(1/3)
Explanation:
The mixed number for the improper fraction 19/3 is 6(1/3).

Express each mixed number as an improper fraction.

Question 13.
4$$\frac{3}{5}$$
4(3/5) =(20 + 3)/5 = 23/5
Explanation:
The improper fraction for the mixed number 4(3/5) is 23/5.

Question 14.
6$$\frac{7}{9}$$
6(7/9) = (54 + 7)/9 = 61/9
Explanation:
The improper fraction for the mixed number 6(7/9) is 61/9.

Question 15.
$$\frac{2}{3}$$ + $$\frac{5}{4}$$
2/3 + 5/4
= (8 + 15)/12
= 23/12
The simplest form of 2/3 + 5/4 is 23/12.
Explanation:
Perform addition operation on above two fractions. Add 2/3 with 5/4 the sum is 23/12.

Question 16.
$$\frac{7}{8}$$ – $$\frac{2}{3}$$
7/8 – 2/3
= (21 – 16)/24
= 5/24
The simplest form of 7/8 – 2/3 is 5/24.
Explanation:
Perform subtraction operation on above two fractions. Subtract 2/3 from 7/8 the difference is 5/24.

Question 17.
1$$\frac{1}{4}$$ + 3$$\frac{2}{5}$$
The mixed fraction 1(1/4) in fraction form as 5/4.
The mixed fraction 3(2/5) in fraction form as 17/5.
1(1/4) + 3(2/5)
= 5/4 + 17/5
= (25 + 68)/20
= 93/20
The simplest form of 1(1/4) + 3(2/5) is 93/20.
Explanation:
Perform addition operation on above two fractions. Add 1(1/4) with 3(2/5) the sum is 93/20.

Question 18.
$$\frac{2}{9}$$ • $$\frac{3}{4}$$
2/9 • 3/4
= 6/36
= 1/6
The simplest form of 2/9 • 3/4 is 1/6.
Explanation:
Perform multiplication operation on above two numbers. Multiply 2/9 with 3/4 the product is 1/6.

Question 19.
1$$\frac{2}{9}$$ • $$\frac{3}{4}$$
1(2/9) • 3/4
= 11/9 • 3/4
= 33/36
The simplest form of 1(2/9) • 3/4 is 33/36.
Explanation:
Perform multiplication operation on above two numbers. Multiply 1(2/9) with 3/4 the product is 33/36.

Question 20.
$$\frac{5}{8}$$ ÷ $$\frac{21}{4}$$
5/8 ÷ 21/4
= 5/8 • 4/21
= 5/2 • 1/21
= 5/42
The simplest form of 5/8 ÷ 21/4 is 5/42.
Explanation:
Perform division operation on above two numbers. Divide 5/8 by 21/4 the result is 5/42.

Question 21.
$$\frac{3}{4}$$ ÷ 1$$\frac{1}{2}$$
3/4 ÷ 1(1/2)
= 3/4 ÷ 3/2
= 3/4 • 2/3
= 1/2
The simplest form of 3/4 ÷ 1(1/2) is 1/2.
Explanation:
Perform division operation on above two numbers. Divide 3/4 by 1(1/2) the result is 1/2.

Multiply or divide.

Question 22.
15.8 • 2.7
15.8 • 2.7
= 42.66
Explanation:
Perform multiplication operation on above two numbers. Multiply 15.8 with 2.7 the product is 42.66.

Question 23.
8.82 ÷ 0.6
8.82 ÷ 0.6
= 14.7
Explanation:
Perform division operation on above two numbers. Divide 8.82 by 0.6 the result is 14.7.

Question 24.
25% of $420 Answer: 25% of$420
= 25/100 • $420 = 1/4 •$420
= $420/4 =$105
Explanation:
Perform multiplication operation. Multiply 25/100 with $420 the product is$105.

Question 25.
115 is what percent of 345?
X% of 345 = 115
x/100 • 345 = 115
x = 115/345 • 100
x = 1/3 • 100
x = 33.33%
115 is 33.33% of 345.

Question 26.
24 boys out of 64 classmates is what percent?
24/64 • 100
= 3/8 • 100
= 75/2
= 37.5%
24 boys out of 64 classmates is 37.5%.

Solve.

Question 27.
A seedling that Jeffrey planted in 2009 was 50 centimeters tall. In 2010, it was 120 centimeters tall.
a) Find the increase in the height of the seedling Jeffrey planted.
$$\frac{70}{50}$$ × 100%