1. Bell Work Jan 28 1) 2)
Obj: I will use percents to determine sales tax, tips, and commissions.

3. Sales Tax = Tax Rate x Purchase Price
Finding Sales Tax
To find sales tax, use the formula:
Sales Tax = Tax Rate x Purchase Price
Ex 1: Find the total cost for a purchase
of $185 if the sales tax rate is 5.5%.
t = x 185
t =
t = 10.18
Total Cost = Cost + Tax =
= $195.18

4. Sales Tax = Tax Rate x Purchase Price
Finding Sales Tax
To find sales tax, use the formula:
Sales Tax = Tax Rate x Purchase Price
Ex 2: The price of a coat is $114 before sales tax. The sales tax is 7%. Find the total cost of the coat.
t = 0.07 x 114
t = 7.98
Total Cost = Cost + Tax =
= $121.98
The total cost of the coat is $

5. Estimating a Tip Step 1: Round the bill to the nearest dollar
Step 2: Find 10% of the bill
Step 3: Find 5% of the bill (1/2 of the 10%)
Step 4: Add steps 2 and 3
The tip is about $8.70.
Ex 3: Estimate a 15% tip
for a bill of $58.20
58.20 ≈ 58
0.1 x 58 = 5.8
𝟏 𝟐 𝐱 𝟓.𝟖=𝟐.𝟗
= 8.7

6. Estimating a Tip Ex 4: Estimate a 15% tip for a bill of $61.80
Step 1: Round the bill to the nearest dollar
Step 2: Find 10% of the bill
Step 3: Find 5% of the bill (1/2 of the 10%)
Step 4: Add steps 2 and 3
61.80 ≈ 62
0.1 x 62= 6.2
𝟏 𝟐 𝐱 𝟔.𝟐=𝟑.𝟏
= 9.3
Ex 4: Estimate a 15% tip
for a bill of $61.80
The tip is about $9.30.

7. Commission = Commission Rate x Sales
Finding a Commission
To find a commission, use the formula:
Commission = Commission Rate x Sales
Ex 5: Find the commission on a $3,200 sale with a commission rate of 6%.
c = 0.06 x 3200
c = 192
The commission is $192.

8. Commission = Commission Rate x Sales
Finding a Commission
To find a commission, use the formula:
Commission = Commission Rate x Sales
Ex 6: Suppose you earn a weekly salary of $800 plus a commission of 3.5% on all sales. Find your earnings for a week with total sales of $1400.
Total Earnings = salary + commission =
c = x 1400
c = 49
My earnings for the week is $849.

9. Commission = Commission Rate x Sales
Finding a Commission
To find a commission, use the formula:
Commission = Commission Rate x Sales
Ex 7: A store pays a 6% commission on the first $500 in sales and 8% on sales over $500. Find the commission on an $800 sale.
c = 0.06 x x 300
c =
c =
The commission is $54.

10. EXIT TICKET Homework: pg 306 + # 1-10, 26-28
Suppose your boss owes you $800, plus a commission of 2.5% on a sale of $ How much does your boss owe you?
What is the total cost of an item costing $35.99 with a 5% sales tax?
Homework: pg # 1-10, 26-28