Solved Questions of Operations on Decimals
1. John had $25.68 and he spent $7.95 at the store. How much money does he has left?
a) 15.23
b) 17.73
c) 18.22
d) 19.13
Answer: b) 17.73
Explanation: Total amount that John had = $25.68
Expenditure = $7.95
Left amount is $25.68 - $7.95 = $17.73
2. A recipe calls for 1/4 cup of sugar. If you want to make half of the recipe, how much sugar do you need?
a) 1.25
b) 0.0125
c) 0.125
d) 125
Answer: c) 0.125
Explanation: 1/4 cup of sugar = 0.25 cup of sugar
Then, multiply 0.25 by 1/2: 0.25 x 1/2 = 0.125
3. A car traveled 50.4 miles on 2.4 gallons of gas. How many miles per gallon did the car get?
a) 18
b) 19
c) 20
d) 21
Answer: d) 21
Explanation: 50.4 miles ÷ 2.4 gallons = 21 miles per gallon
Therefore, the car got 21 miles per gallon.
4. Find the product of 56.357 × 3.1
a) 174.7067
b) 123.2455
c) 120.3452
d) 178.2137
Answer: a) 174.7067
Explanation: Perform the multiplication ignoring the decimal points in multiplicand and multiplier.
Since, 56357 × 31 = 1747067
Here the multiplicand contains three decimal places and the multiplier contains one decimal place, so together the product must contain four decimal places.
Therefore, 56.357 × 3.1 = 174.7067
5. George has $24.5 of his monthly allowance left with him. He spends it over the course of a week such that his daily expenses stay the same. How much money does he spend every day?
a) $2.3
b) $3.5
c) $4.2
d) $5.6
Answer: b) $3.5
Explanation: Money that George has with him =$24.5
This amount is equally spent in a week or 7 days.
Amount spent by George every day = 24.5 ÷ 7 = $3.5
Practice Questions of Operations on Decimals
1. If you spend $15.75 on 2.5 liters of orange juice, how much does one liter of orange juice cost?
a) $6.0
b) $6.30
c) $6.45
d) $7.00
Answer: b) $6.30
2. A bag of candy contains 0.75 kilograms of candy. If each piece of candy weighs 0.05 kilograms, how many pieces of candy are in the bag?
a) 5
b) 10
c) 15
d) 20
Answer: c) 15
3. Divide 0.8 by 0.05 and express the answer in decimal form.
a) $27
b) $12
c) $18
d) $16
Answer: d) $16
4. What is the result of 6.7 x 4.9?
a) 32.83
b) 39.23
c) 43.28
d) 53.22
Answer: a) 32.83
5. What is the result of 456.78 divided by 7.23?
a) 60.32
b) 61.63
c) 63.17
d) 65.20
Answer: c) 63.17
6. Subtract 467.9 from 798.3.
a) 300.2
b) 319.4
c) 328.3
d) 330.4
Answer: d) 330.4
7. What is the quotient of 8.9 divided by 3.1?
a) 5.43
b) 2.87
c) 3.45
d) 4.67
Answer: b) 2.87
8. Evaluate the expression: 9.1 - 5.7 + 2.3.
a) 3.2
b) 4.5
c) 5.7
d) 7.2
Answer: c) 5.7
9. Find the product of 432.01 × 4.2.
a) 1814.442
b) 1804.424
c) 1184.244
d) 1841.224
Answer: a) 1814.442
10. Divide 45.89 by 6.5.
a) 6.23
b) 7.06
c) 7.34
d) 8.25
Answer: b) 7.06
