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Math 7 · Unit 4, Lesson 6: Equivalent Expressions · Tile 2 of 4

What the Parts Mean

Coefficients, constants, and the story

Coefficients, constants, and the story

In a real situation, every part of an expression means something. The constant is the amount that stays the same no matter what. The coefficient is the amount for each one of the variable. Say what each part means in words.

A gym charges 25 dollars to join and 12 dollars each month:

The expression 12m plus 25 with each part labeledAn arrow from 12 says coefficient, 12 dollars for each month. An arrow from m says variable, the number of months. An arrow from 25 says constant, the one time joining fee.12m+25coefficient: 12 dollars for each monthvariable: the number of monthsconstant: the one time joining fee
12m + 25: the 12 is the each amount, m is the number of months, and 25 is the once amount.

Elle and Finn

ElleMath-speak

In context, the coefficient is the amount per one unit of the variable, and the constant is a fixed amount.

FinnPlain English

The number stuck to the letter is the each amount. The number by itself is the once amount.

Watch it work

Last week, the total profit p went up by 5%.

p + 0.05p write it1.05p rewrite it

What do you notice? p + 0.05p shows the old profit plus the increase. 1.05p shows the same total in one step: multiply by 1.05. That is the percent increase idea from Unit 2, Lesson 5, Percent Increase and Decrease.

The same idea going down. A shirt is 20% off.

p − 0.2p the price minus the discount0.8p you pay 80% of the price

Let me try a few

NC standard: NC.7.EE.2.

Where to go next

Let me try a few6 problems on what the parts mean. Next: Tile 3, Pictures and StoriesRewrite it to see something new All tilesAll 4 parts of this lesson. Tell us what you thought about this tileA few quick questions about just this tile. It takes a few minutes, and opens in a new tab so you keep your place.