Common Core: 7th Grade Math : Rewrite an Expression: CCSS.Math.Content.7.EE.A.2

Study concepts, example questions & explanations for Common Core: 7th Grade Math

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Example Questions

Example Question #11 : Rewrite An Expression: Ccss.Math.Content.7.Ee.A.2

Christina is going to buy a new camera. The camera costs \(\displaystyle \$220\) plus an \(\displaystyle 8\%\) sales tax. What is the total price that Christina will pay for her new camera? 

 

Possible Answers:

\(\displaystyle \$239.60\)

\(\displaystyle \$237.60\)

\(\displaystyle \$240.20\)

\(\displaystyle \$230\)

\(\displaystyle \$245.20\)

Correct answer:

\(\displaystyle \$237.60\)

Explanation:

We know that Christina is going to pay \(\displaystyle 100\%\) of the \(\displaystyle \$220\) camera because that is the total cost. Plus, she is going to pay \(\displaystyle 8\%\) of the \(\displaystyle \$220\) because that is the sales tax. 

First, we need to convert our percentages into decimals in order to multiply. 

\(\displaystyle 100\%\rightarrow1.00\)

\(\displaystyle 8\%\rightarrow0.08\)

Next, we can write a numeric expression and solve:

\(\displaystyle 1.00(\$220)+0.08(\$220)=1.08(\$220)\)

\(\displaystyle \$220+\$17.60=\$237.60\)

Example Question #31 : Expressions & Equations

Addison is going to buy a new computer. The computer costs \(\displaystyle \$575\) plus an \(\displaystyle 8\%\) sales tax. What is the total price that Addison will pay for her new computer? 

Possible Answers:

\(\displaystyle \$621\)

\(\displaystyle \$622\)

\(\displaystyle \$620\)

\(\displaystyle \$618\)

\(\displaystyle \$619\)

Correct answer:

\(\displaystyle \$621\)

Explanation:

We know that Addison is going to pay \(\displaystyle 100\%\) of the \(\displaystyle \$575\) computer because that is the total cost. Plus, she is going to pay \(\displaystyle 8\%\) of the \(\displaystyle \$575\) because that is the sales tax. 

First, we need to convert our percentages into decimals in order to multiply. 

\(\displaystyle 100\%\rightarrow1.00\)

\(\displaystyle 8\%\rightarrow0.08\)

Next, we can write a numeric expression and solve:

\(\displaystyle 1.00(\$575)+0.08(\$575)=1.08(\$575)\)

\(\displaystyle \$575+\$46=\$621\)

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