Grade 8 Mental Math Workout

Grade 8 Mental Math Workout

Read each question carefully and answer using mental calculation strategies. Try to avoid using a calculator or writing down intermediate steps unless absolutely necessary. Good luck!

Estimation Challenge

Estimate the answer to each problem. Circle the closest estimate.

1. A concert hall has 48 rows with 23 seats in each row. Approximately how many seats are there in total?

2. If a shirt costs $29.95 and you buy 3 of them, what is your approximate total cost?

Percentage Puzzles

Mentally calculate the following percentages.

1. 10% of 150 is  .

2. 25% of 80 is  .

3. 50% of 320 is  .

4. 75% of 120 is  .

5. 20% of 90 is  .

Quick Calculations

Solve the following problems mentally.

1. What is 18 + 27?

2. What is 53 - 19?

3. What is 15 x 6?

4. What is 84 ÷ 7?

Mental Math True or False

Determine if the following statements are true or false using mental calculation.

1. 30% of 200 is 60.

2. The product of 12 and 11 is 132.

Number Line Operations

Use the number line to visualize the following operations and mentally find the answer.

1. Start at -3, add 7.

2. Start at 5, subtract 8.

Problem Solving

Solve the following word problem using mental math strategies. Explain your thought process.

1. Sarah bought a book for $12.50 and a coffee for $3.75. If she paid with a $20 bill, how much change did she receive?