Addition & Subtraction Math Worksheet for 15-Year-Olds — Printable Practice

Free worksheet covering Math for age 15 students. Created with Learning Corner's AI-powered tools.

Get personalized worksheets for your own interests and needs

Try Worksheets Now
PDF

Instructions

Solve the following problems, showing your work where necessary. Pay close attention to negative signs, decimal points, and common denominators. Simplify all fractions and algebraic expressions.

Part 1: Integer Operations

Calculate the value of each expression.

  1. (-34) + 19 = ?
  2. 21 - (-15) = ?
  3. (-8) - 22 = ?
  4. -16 + (-25) = ?
  5. 150 - 320 = ?

Part 2: Decimal Arithmetic

Calculate the value of each expression. Be careful to align the decimal points.

  1. 351.8 + 92.47 = ?
  2. 88.2 - 19.551 = ?
  3. A diver is at a depth of -45.6 meters. She ascends 18.8 meters. What is her new depth?
  4. Your lunch bill is $23.85. You pay with two $20 bills. How much change do you receive?

Part 3: Fraction Arithmetic

Calculate the value of each expression. Express your answers as simplified fractions or mixed numbers.

  1. 5/8 + 1/6 = ?
  2. 7/9 - 2/3 = ?
  3. 4 1/2 + 2 3/5 = ?
  4. 5 1/4 - 1 5/6 = ?

Part 4: Simplifying Algebraic Expressions

Combine like terms to simplify each expression.

  1. (8x - 5y) + (3x + 9y)
  2. (12a + 7b - 4) + (-5a - 10b + 2)
  3. (6m - 2n) - (9m + 4n)
  4. (3x² + 5x - 8) - (7x² - 2x - 11)

Part 5: Word Problems

Read each problem carefully and solve.

  1. The stock price of a company started the day at $56.75 per share. During the day, it dropped by $4.10, and then later rose by $2.55. What was the final stock price at the end of the day?
  2. You are baking a cake and need a total of 4 1/2 cups of flour. You have already added 2 1/3 cups. How much more flour do you need to add?


Answer Key

Part 1: Integer Operations

  1. -15
  2. 36
  3. -30
  4. -41
  5. -170

Part 2: Decimal Arithmetic

  1. 444.27
  2. 68.649
  3. -45.6 + 18.8 = -26.8 meters
  4. $40.00 - $23.85 = $16.15

Part 3: Fraction Arithmetic

  1. 15/24 + 4/24 = 19/24
  2. 7/9 - 6/9 = 1/9
  3. 9/2 + 13/5 = 45/10 + 26/10 = 71/10 or 7 1/10
  4. 21/4 - 11/6 = 63/12 - 22/12 = 41/12 or 3 5/12

Part 4: Simplifying Algebraic Expressions

  1. 11x + 4y
  2. 7a - 3b - 2
  3. 6m - 2n - 9m - 4n = -3m - 6n
  4. 3x² + 5x - 8 - 7x² + 2x + 11 = -4x² + 7x + 3

Part 5: Word Problems

  1. $56.75 - $4.10 + $2.55 = $52.65 + $2.55 = $55.20
  2. 4 1/2 - 2 1/3 = 9/2 - 7/3 = 27/6 - 14/6 = 13/6 or 2 1/6 cups
With Worksheets, you can:
  • Reinforce key concepts
  • Provide hands-on practice
  • Customize exercises to fit your needs
  • Track your student's improvement
Try Worksheets Now