📝 Part 1: Identifying Variables and Constants

1. Circle the variables in each expression:

a) 3x + 7 b) 2y - 5 c) 4a + 3b d) 9 + m

2. Underline the constants in each expression:

a) 5x + 12 b) 8 - 3y c) 7a + 2b - 1 d) x + 15

3. Which of the following are algebraic expressions? Check all that apply:

3x + 5

7

y - 4

x

2a + 3b

15

🔢 Part 2: Writing Algebraic Expressions

4. Write an algebraic expression for each situation:

a) A number x increased by 8: _______________

b) Five times a number y: _______________

c) A number m decreased by 12: _______________

d) Three times a number plus 7: _______________

e) The sum of two numbers a and b: _______________

5. Sarah has some stickers. Her brother gives her 6 more stickers. If we use s to represent the number of stickers Sarah originally had, write an expression for the total number of stickers she has now:

6. A rectangle has a length of 10 centimetres and a width of w centimetres. Write an expression for the perimeter of the rectangle:

🧮 Part 3: Substituting Values

7. Find the value of each expression when x = 4:

a) x + 9 = _____ + 9 = _____

b) 3x = 3 × _____ = _____

c) 2x + 5 = 2 × _____ + 5 = _____ + 5 = _____

d) x - 1 = _____ - 1 = _____

8. Find the value of each expression when y = 7:

a) y + 3 = _____

b) 5y = _____

c) 4y - 10 = _____

d) 2y + 8 = _____

9. If a = 3 and b = 5, find the value of:

a) a + b = _____

b) 2a + b = _____

c) 3a + 2b = _____

d) a + 3b = _____

🎯 Part 4: Multiple Choice

10. Which expression represents "a number n multiplied by 6"?

n + 6

6n

n - 6

n ÷ 6

11. If x = 2, what is the value of 3x + 4?

9

10

11

14

12. In the expression 5y - 8, which is the constant?

5

y

8

5y

🔍 Part 5: Real-World Applications

13. A taxi charges $3.50 plus $2.20 per kilometre. If k represents the number of kilometres travelled, write an expression for the total cost in dollars:

14. Using your expression from question 13, calculate the cost of a 8-kilometre taxi ride:

15. The temperature in degrees Celsius can be converted to Fahrenheit using the expression 9c ÷ 5 + 32, where c is the temperature in Celsius. Find the Fahrenheit temperature when c = 25°C:

16. Explain in your own words what a variable is and give an example:

17. Explain the difference between a variable and a constant: