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
Answer:
-3 < 5
Explanation:
Compare the above two numbers. The number -3 is less than 5.
Question 2.
-7 ? -12
Answer:
-7 > -12
Explanation:
Compare the above two numbers. The number -7 is greater than -12.
Question 3.
10 ? -16
Answer:
10 > -16
Explanation:
Compare the above two numbers. The number 10 is greater than -16.
Question 4.
-28 ? 0
Answer:
-28 < 0
Explanation:
Compare the above two numbers. The number -28 is less than 0.
Question 5.
\(\frac{1}{2}\) ? \(\frac{3}{4}\)
Answer:
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\(\frac{2}{3}\)
Answer:
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
Answer:
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
Answer:
-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
Answer:
75 – (18 + 2) ∙ 3 Given
= 75 – 20 ∙ 3 Perform operation in parentheses
= 75 – 60 Multiply
= 15 subtract
Question 10.
15 ∙ (40 ÷ 8) + 72
Answer:
15 ∙ (40 ÷ 8) + 72 Given
= 15 ∙ 5 + 72 Perform operation in parentheses
= 75 + 72 Multiply
= 147 Add
= 147
Express each improper fraction as a mixed number.
Question 11.
\(\frac{12}{17}\)
Answer:
Question 12.
\(\frac{19}{3}\)
Answer:
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\(\frac{3}{5}\)
Answer:
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\(\frac{7}{9}\)
Answer:
6(7/9) = (54 + 7)/9 = 61/9
Explanation:
The improper fraction for the mixed number 6(7/9) is 61/9.
Add or subtract. Express your answer in simplest form.
Question 15.
\(\frac{2}{3}\) + \(\frac{5}{4}\)
Answer:
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.
\(\frac{7}{8}\) – \(\frac{2}{3}\)
Answer:
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\(\frac{2}{5}\)
Answer:
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.
Multiply or divide. Express your answer in simplest form.
Question 18.
\(\frac{2}{9}\) • \(\frac{3}{4}\)
Answer:
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\(\frac{2}{9}\) • \(\frac{3}{4}\)
Answer:
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.
\(\frac{5}{8}\) ÷ \(\frac{21}{4}\)
Answer:
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\(\frac{1}{2}\)
Answer:
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
Answer:
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
Answer:
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?
Answer:
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?
Answer:
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.
Answer:
A seedling that Jeffrey planted in 2009 was 50 centimeters tall.
In 2010, it was 120 centimeters tall.
120 – 50 = 70 centimeters.
The height of the seedling Jeffrey planted is increased by 70 centimeters.
b) Find the percent increase in the height of the seedling.
Answer:
Percent in the increase in height :
\(\frac{70}{50}\) × 100%
= 1.4 × 100%
= 140%
70 centimeters ; 140%