Decimal Word Problems
Question:
A bakery has 12.5 kg of flour. It uses 3.75 kg to make bread.
How much flour is left?
8.75kg
Question:
Jordan has $25 and spends $8.75 on a book.
How much money does Jordan have left?
$16.25
Question:
A ribbon is 3.5 meters long. How many centimeters long is it?
350cm
Question:
Mia ran 2.4 miles on Monday and 1.8 miles on Tuesday.
How many miles did she run altogether?
4.2 miles
Question:
A student says:
“If 3 notebooks cost $9.60, then 1 notebook costs $3.20.”
Is the student correct?
Answer: Yes!
$9.60 ÷ 3 = $3.20
Question:
Ava buys 4 notebooks for $2.35 each.
How much does she spend altogether?
$9.40
A teacher buys 7 folders for $1.35 each.
How much does she spend?
$9.45
Question:
A package weighs 2.75 kilograms.
How many grams does it weigh?
2,750 grams
Question:
Mia ran 2.4 miles on Monday and 1.8 miles on Tuesday.
How many miles did she run altogether?
Answer: 24 cups
6 ÷ 0.25 = 24
Question:
A student says:
“2.5 kilograms is the same as 250 kilograms because 1 kilogram equals 100 grams.”
Is the student correct?
Answer: No.
1 kg = 1,000 g
So:
2.5 kg = 2,500 g
A water tank contains 15.6 liters. A scientist removes 4.25 liters and then adds 2.8 liters.
How much water is in the tank now?
Answer: 14.15 liters
15.6 − 4.25 = 11.35
11.35 + 2.8 = 14.15
Question:
A student has $50. She buys a game for $18.75 and a book for $7.50.
How much money does she have left?
Answer: $23.75
$18.75 + $7.50 = $26.25
$50 − $26.25 = $23.75
A runner travels 4.2 kilometers in the morning and 850 meters in the afternoon.
How many kilometers does the runner travel altogether?
Answer: 5.05 kilometers
850 m = 0.85 km
4.2 + 0.85 = 5.05 km
A large box weighs 3 times as much as a small box. The small box weighs 1.4 kg.
What is the mass of the large box?
Answer: 4.2 kg
1.4 × 3 = 4.2 kg
Question:
A student solves:
$20 − $6.75 = $14.25
Then says, “I have $14.25 left.”
Is the student correct?
Answer: Yes!
20.00 − 6.75 = 13.25
Correction: No!
The correct answer is $13.25.
The student made an error when subtracting the decimals.
Question:
A teacher has $75. She buys 6 packs of markers for $4.25 each.
How much money does she have left?
Answer: $49.50
6 × $4.25 = $25.50
$75 − $25.50 = $49.50
Question:
Five identical water bottles cost $18.75 altogether.
What is the cost of one bottle?
Answer: $3.75
$18.75 ÷ 5 = $3.75
Question:
A recipe needs 3.5 kilograms of flour. A baker already has 1,250 grams.
How many grams of flour does the baker still need?
Answer: 2,250 grams
3.5 kg = 3,500 g
3,500 − 1,250 = 2,250 g
Question:
Three identical bags and two identical boxes have a total mass of 14.4 kg.
Each box weighs 3 times as much as one bag.
What is the mass of one bag?
Answer: 2.4 kg
Let one bag = 1 part.
Each box = 3 parts.
So:
3 bags + 2 boxes = 3 + 6 = 9 parts
14.4 ÷ 9 = 1.6 kg
Correction: One bag = 1.6 kg.
Each box = 4.8 kg.
Answer: 1.6 kg
Question:
A student says:
“If a large package is 3 times as heavy as a small package, then three small packages and one large package must weigh the same.”
Is this always true?
Answer: Yes.
If one small package weighs 1 kg, then a large package weighs 3 kg.
Three small packages:
1 + 1 + 1 = 3 kg
So they have the same mass.
Question:
A science class has 18.5 liters of water. They use 4.75 liters for one experiment and 3.25 liters for another. The remaining water is divided equally among 5 containers.
How much water goes into each container?
Answer: 2.1 liters
18.5 − 4.75 = 13.75
13.75 − 3.25 = 10.5
10.5 ÷ 5 = 2.1 liters
Question:
A teacher receives $120 to spend on her classroom.
She spends $27.50 on notebooks. She uses 1/2 of the remaining money to buy science supplies.
How much money does she have left?
Answer: $46.25
First:
$120 − $27.50 = $92.50
Then:
$92.50 ÷ 2 = $46.25
Question:
A piece of wire is 18 meters long. A student uses 4.5 meters to build one model and 375 centimeters to build another.
How many meters of wire are left?
Answer: 9.75 meters
375 cm = 3.75 m
18 − 4.5 − 3.75 = 9.75 m
Question:
A student has some money.
After spending $12.50, she has $37.50 left.
How much money did she have at the beginning?
Answer: $50
$37.50 + $12.50 = $50
Question:
A student has some money.
They spend $18.40 and then spend $7.60. After both purchases, they have $24 left.
How much money did they start with?
Answer: $50
Work backward:
$18.40 + $7.60 = $26
Then:
$26 + $24 = $50