🌟 Introduction to Algebraic Expressions 🌟

Hi my brilliant Grade 6 algebra explorers! 🌟

Today we begin a very exciting part of math — Algebra! We’re going to learn how to use variables (letters) to represent unknown numbers. This helps us solve real problems and describe patterns. You’re going to love it! Let’s get started! 🔤

1. What is a Variable?

A variable is a letter that stands for a number we don’t know yet.

Common variables: x, y, n

Example: “A number plus 5” → x + 5

2. What is an Algebraic Expression?

An algebraic expression is a combination of numbers, variables, and operations (+, −, ×, ÷).

Examples:

• x + 7 → “a number plus 7”
• 3y → “3 times a number”
• 2x + 5 → “twice a number plus 5”
• n − 4 → “a number minus 4”

3. Evaluating Algebraic Expressions

To evaluate = replace the variable with a number and calculate.

Example: Evaluate 3x + 4 when x = 5

3 × 5 + 4 = 15 + 4 = 19

Example: Evaluate 2y − 6 when y = 10

2 × 10 − 6 = 20 − 6 = 14

4. Let’s Practice Together! 🎉

Question 1:

Write an expression: “A number times 4 plus 9”

4n + 9 ⭐

Question 2:

Evaluate 5x + 2 when x = 6

5×6 + 2 = 32 ⭐

Question 3:

Write an expression: “12 less than a number”

n - 12 ⭐

Question 4:

Evaluate 2y − 7 when y = 10

2×10 − 7 = 13 ⭐

Question 5 (Real Life):

You buy x pencils that cost 3 dollars each and pay a $2 fee. Write an expression for the total cost. Then find the cost if x = 8.

Expression: 3x + 2
When x = 8: $26 ⭐

6. Real Life in Canada 🇨🇦

Buying hockey cards: 5x + 3 dollars
Monthly phone bill: 45 + 0.15x (per minute)
Savings: You save $12 per week → 12w
Temperature: It was x degrees and dropped 7 degrees

You are an Algebraic Expression Expert! 🏆

Amazing work today! You now understand variables and algebraic expressions.

This is the beginning of real algebra — you’re doing wonderfully!

I’m so proud of you,

Keep using letters for unknown numbers,
Mrs. Brenda ❤️

🔤✨📐