Discovering Variables in Math Expressions
Grade 6 Mathematics Understanding Unknown Quantities Building Foundations for Algebra
What's in the Mystery Box?
Look at this expression: 3 + __ = 8 What number could fill the blank? How do we represent unknown numbers in math?
What is a Variable?
A letter or symbol that represents an unknown number Can stand for numbers we don't know yet Can represent numbers that change Examples: x, y, z, n, m
Variables vs. Constants
{"left":"Variables (Unknown/Changing)\nx, y, z\nCan be different numbers\nRepresents what we're solving for","right":"Constants (Known Numbers)\n3, 7, 15\nAlways the same value\nNumbers we already know"}
Real-Life Variables
Your age next year = your age now + 1 If your current age is 'a', then next year you'll be 'a + 1' Number of cookies in a jar = 'c' Time to finish homework = 't' minutes
Identifying Variables in Expressions
In 5 + x: the variable is 'x' In y - 4: the variable is 'y' In 2m: the variable is 'm' Variables can be any letter!
Variable Detective Challenge
Find the variables in these expressions: 7 + n k - 3 4 × p Write your answers on your mini whiteboard!
Remember This!
Variables are mathematical helpers that let us work with unknown or changing numbers! They make math more powerful and flexible.