Real-world fraction multiplication · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.
Fraction multiplication in real life
Mathematics · Fractions · ages 10-11
Name ______________________ Date ____________
A hot cocoa recipe uses 2/3 cup of milk. You only want to make 3/4 of the recipe. How much milk do you need?
1/2 cup
1/3 cup
2/7 cup
5/7 cup
A recipe needs 3/4 cup of oil for 1 batch. Which multiplication tells you how much oil for 2 batches?
3/4 x 2
3/4 + 2
3/4 divided by 2
Rounding 2 1/3 to about 2 before you solve helps you check if your final answer is reasonable.
Circle one: TrueFalse
This picture shows 3/4 of a garden shaded. The garden is 8 square meters. Which multiplication finds the shaded area?
3/4 x 8
3/4 + 8
4 x 8
A granola recipe uses 1 1/2 cups of oats for one batch. How many cups of oats do you need for 2 2/3 batches?
4 cups
3 1/3 cups
4 1/2 cups
3 5/6 cups
Which drawing shows the multiplication 1/2 times 1/3?
A rectangle split into 2 equal parts with 1 part shaded, then the shaded part split into 3 equal pieces with 1 piece double-shaded.
Two separate rectangles, one split into 2 parts and one split into 3 parts, sitting side by side.
A rectangle split into 5 equal parts with 1 part shaded.
One whole circle shaded in and another circle half shaded.
A pancake recipe needs 2 1/3 cups of flour for one batch. You want to make 1 1/2 batches. How much flour do you need?
3 1/2 cups
3 1/3 cups
4 1/3 cups
2 1/2 cups
Jamal estimates that 3 1/2 times 2 1/4 is about 8. Which check shows his estimate is reasonable?
Round 3 1/2 to 4 and 2 1/4 to 2. Since 4 times 2 is 8, and the exact answer 7 7/8 is very close to 8, his estimate is reasonable.
Estimates must give the exact answer, so since 4 times 2 is 8, the exact answer must be exactly 8.
Multiplying makes numbers bigger, so the answer has to be more than 8 and 8 is too small.
Round 2 1/4 up to 3. Since 3 1/2 times 3 is 10 1/2, the estimate of 8 is wrong.
A triangular sail has a base of 3 1/2 meters and a height of 2 1/4 meters. What is the area of the sail?
3 15/16 square meters
7 7/8 square meters
3 3/8 square meters
6 1/8 square meters
Diego solves '2/3 of a 1 1/2 hour movie' by multiplying 2/3 x 1, getting 2/3 hour. What did he do wrong?
He needed to divide by 3 first
He used 1 instead of the full mixed number 1 1/2
He should have added instead of multiplied
Answer key
For grown-ups. Fold this page away before handing over the rest.
Fraction multiplication in real life W1-mt_lvaSGHwvQ5-s1
1/2 cup · 3/4 of 2/3 is 2/3 times 3/4, which equals 1/2 cup of milk.
3/4 x 2 · Scaling a recipe up or down means multiplying the amount per batch by the number of batches.
True · Estimating with rounded numbers gives you a quick way to check your exact answer.
3/4 x 8 · The shaded part is 3/4 of the whole garden, so you multiply 3/4 by the total area.
4 cups · 1 1/2 times 2 2/3 equals exactly 4 cups of oats.
A rectangle split into 2 equal parts with 1 part shaded, then the shaded part split into 3 equal pieces with 1 piece double-shaded. · 1/2 times 1/3 means find 1/3 of 1/2. Shade half, split that half into thirds, and double-shade one piece. That piece is 1/6 of the whole, and 1/2 times 1/3 equals 1/6.
3 1/2 cups · 2 1/3 times 1 1/2 equals 3 1/2, so you need 3 1/2 cups of flour.
Round 3 1/2 to 4 and 2 1/4 to 2. Since 4 times 2 is 8, and the exact answer 7 7/8 is very close to 8, his estimate is reasonable. · Rounding each mixed number to the nearest whole gives 4 times 2 equals 8, and the exact answer 7 7/8 sits right next to 8, so the estimate checks out.
3 15/16 square meters · The area of a triangle is 1/2 times base times height. That gives 63/16, which is 3 15/16 square meters.
He used 1 instead of the full mixed number 1 1/2 · Diego dropped the 1/2 from the mixed number. He should multiply 2/3 x 1 1/2, not 2/3 x 1.