Solving for Unknowns: Math Variables Quiz for Grade 4

1. Sarah has 5 apples. She buys some more apples and now has 12 apples. How many apples did she buy? (Let x be the number of apples Sarah bought.)

• 5

• 3

• 10

• 7

2. Tom has 3 times as many marbles as Jerry. If Jerry has y marbles and together they have 48 marbles, how many marbles does Tom have? (Set up an equation to find y.)

• 12

• 18

• 24

• 36

3. A book costs $15. If you buy x books, how much will you spend in total? (Write an equation to represent the total cost.)

• Total Cost = 15 + x

• Total Cost = 15 / x

• Total Cost = 15 - x

• Total Cost = 15 * x

4. Lisa has 20 stickers. She gives away some stickers to her friends and now has 12 left. How many stickers did she give away? (Let z be the number of stickers given away.)

• 15

• 5

• 8

• 10

5. A box can hold 10 toys. If you have x boxes, how many toys can you hold in total? (Create an equation to express the total number of toys.)

• total_toys = 5 * x

• total_toys = 10 * x

• total_toys = x + 10

• total_toys = 10 + x

6. There are 30 students in a class. If x students are absent today, how many students are present? (Write an equation to find the number of present students.)

• 30 + x

• 30 * x

• 30 - x

• x - 30

7. A farmer has 50 apples. He sells some apples and has 30 left. How many apples did he sell? (Let a be the number of apples sold.)

• 15

• 25

• 10

• 20

8. Emma has 4 times as many crayons as her brother. If her brother has b crayons, how many crayons does Emma have? (Set up an equation to express Emma's crayons.)

• 4b

• 3b

• 2b

• b

9. A pack of gum costs $2. If you buy y packs, how much do you spend? (Write an equation to find the total cost.)

• total cost = 2 + y

• total cost = 2y

• total cost = 3y

• total cost = y/2

10. There are 60 candies in a jar. If you eat c candies, how many candies are left in the jar? (Create an equation to find the remaining candies.)

• 60 - c

• c * 60

• 60 + c

• c - 60