7.1 – Writing Algebraic Expressions
Objective…
Vocabulary…
Term
Variable
Definition
Examples
Algebraic
Expression
Terms
Part A: Use variables to represent unknown numbers and write addition expressions
1)
A 5-inch ribbon is taped to an 8-inch ribbon. What is the total length of the
two ribbons?
Bar model…
Math Statement
2)
A ribbon of unknown length is taped to a 9-inch ribbon. What is the total
length of the two ribbons?
Bar model…
Math Statement
Part B: Use variables to write subtraction expressions
1)
A straw of length 10 centimeters is cut from a straw of length 24 centimeters.
What is the length of the remaining straw?
Bar model…
Math Statement
7.1 – Writing Algebraic Expressions
2)
A straw of length 6 centimeters is cut from a straw of length y centimeters.
What is the length of the remaining straw?
Bar model…
Math Statement
Practice…write an algebraic expression for each of the following
1)
The sum of m and 10:
2)
The difference of “7 less than y:”
3)
Jim is now z years old.
a. His brother is 4 years older than Jim. Find his brother’s age in terms of z.
b. His sister is 3 years younger than Jim. Find his sister’s age in terms of z.
Part C: Use variables to write multiplication expressions
1)
There are 12 crackers in each box. How many crackers are there in 2 boxes?
Bar model…
Math Statement
2)
There are z crackers in each box. How many crackers are there in 4 boxes?
Bar model…
Math Statement
7.1 – Writing Algebraic Expressions
Part D: Use variables to write division expressions
1)
A 12-inch rod is divided into 3 parts of equal length. What is the length of each
part?
Bar model…
Math Statement
2)
A rod of length w inches is divided into 7 parts of equal length. What is the
length of each part?
Bar model…
Math Statement
Practice…write TWO algebraic expressions for each of the following
1)
The product of z and 6:
2)
The quotient of x and 8:
3)
Mia bought a pair of shows for p dollars. She also bought a dress that cost 5
times as much as the shoes, and a belt that cost ¼ f the price of the shoes.
a. Find the cost of the dress in terms of p:
b. Find the cost of the belt in terms of p