1. Writing Expressions

2. We need to translate words in mathematical symbols
We need to translate words in mathematical symbols. Here are some words you should know.
Operation
Verbal Phrase
Expression
Addition: sum, plus, total, more than, increased by.
The sum of 2 and a number x
2+x
A number n plus 7
n+7
Subtraction: difference, less than, minus, decreased by.
The difference of a number n and 6
n-6
A number y minus 5
y-5
Multiplication: times, product, multiplied by, of.
12 times a number y
12y
1/3 of a number x
1/3(x)
Division: Quotient, divided by, divided into.
The quotient of a number k and 2
k/2

3. Translate these verbal phrases into expressions…
4 Less than the quantity 6 times a number n.
3 times the sum of 7 and a number y.
The difference of 22 and the square of a number m.
The quotient when the quantity 10 plus a number x is divided by 2

4. Let’s try it with a word problem…
A piece of ribbon L feet long is cut from a ribbon 8 feet long. Write an expression for the length (in feet) of the remaining piece.

5. Let’s try another…
You work with 5 other people at an ice cream stand. All the worker put their tips into a jar and share the amount in the jar equally a the end of the day. Write an expression for each person’s share (in dollars) for the tips.

6. Let’s Talk About Rate

7. Here’s some vocab… Rate Unit Rate
Is a fraction that compares 2 quantities measured in different units.
Unit Rate
When the denominator of the fraction is 1 unit.

8. Here’s an example of a problem involving rate…
A car travels 110 miles in 2 hours. Find the unit rate.
The unit rate is 55 miles per hour, or 55mi/h, or 55mph

9. Here’s one for you to try…
Your basic monthly charge for cell phone service is $30, which includes 300 free minutes. You pay a fee for each extra minute you use. One month you paid $3.75 for 15 extra minutes. Find your total bill if you use 22 extra minutes.