Marta's customer bought 4 large oranges at $0.75 each and 8 small oranges at $0.50 each plus tax was a total of $7.49. She used t to represent the amount of tax. Explain her errors in the diagram.

The total, 7.49, should be the top bar, and the variable, t, should be one of the partial bars. The prices for a certain number of oranges is also incorrect. $0.75 should be multiplied by 4 and $0.50 multiplied by 8.

Given:

4 large oranges @ 0.75 each

8 small oranges @ 0.50 each

total amount paid: 7.49 including sales tax.

4 (0.75) = 3.00

8 (0.50) = 4.00

3 + 4 = 7

7 + t = 7.49

t = 7.49 - 7

t = 0.49 total amount of tax paid.

0.49/7 = 0.07 sales tax rate

the sales tax rate is 7%

4 (0.75) + 8 (0.5) = 7

7 x 0.07 = 0.49

7 + 0.49 = 7.49