What Are Variable Expressions?
Variables are like mystery numbers!
A variable expression is a math phrase that uses numbers, variables (like x or y), and operation signs (+, -, ×, ÷). We use variables when we don't know a number yet or when the number can change.
For example: x + 5 means "some number plus five"
How to Write Variable Expressions
1️⃣ Find the variable - What number don't you know? Give it a letter name!
2️⃣ Look for key words - "More than" means +, "times" means ×, etc.
3️⃣ Put it together - Combine the numbers and variables with the right operations
Let's Practice Together!
Example 1: The Cookie Jar
Sarah has some cookies in a jar. She adds 3 more cookies. How would you write this as an expression?
We don't know how many cookies Sarah started with, so we'll use c for cookies.
"Adds 3 more" means we use + 3
The expression is: c + 3
Example 2: Toy Cars
Jamal has 4 times as many toy cars as his friend Alex. If Alex has a cars, how many does Jamal have?
"Times" means we use multiplication (×)
"4 times as many" means we multiply Alex's cars by 4
The expression is: 4 × a or 4a
Parent Tips 🌟
- Make it real: Use everyday situations like sharing snacks or counting toys to practice writing expressions.
- Start simple: Begin with addition and subtraction before moving to multiplication and division.
- Use manipulatives: Counters, blocks, or drawings help visualize what the variables represent.