Module #2: Proportional Reasoning with Percents

Module #2: Proportional Reasoning with Percents

Make sure you have a calculator

Percent Change Formula

 $\left(\frac{New\ Value\ -\ Original\ Value\ }{Original\ Value\ }\right)\ \times\ 100$  

Multiple Choice

The iPhone 12 when it originally released was priced at $900. After a successful first week, Apple decided to increase the price to $990. What is the percent increase of the price?

• 20% increase

• 0.1% increase

• 10% increase

• 15% increase

Multiple Choice

When the iPhone 12 became available the iPhone 11 dropped in price. The price went from $850 to $725. What is the percent decrease in the price?

• 12.5% decrease

• 14.7% decrease

• 17% decrease

• 20% decrease

Calculating Discounts

Finding the cost with a Discount in 3 steps:

Step One: Turn the Percent into a Decimal (divide by 100)

Step Two: Multiply the Decimal times the Original Cost

Step Three: Subtract the product from the Original Cost

Multiple Choice

For the beginning of 2021, Hulu is running a special 20% discount to get more subscribers. Hulu Premium originally costs $13 per month. What is the discounted monthly cost?

• $8.60

• $9.50

• $12.25

• $10.40

Calculating Markup

Finding Cost including Markup in 3 steps:

Step One: Turn the Percent into a Decimal (divide by 100)

Step Two: Multiply the Decimal times the Original Cost

Step Three: Add the product to the Original Cost

Multiple Choice

The price of a car was marked up by 5%. If the original cost of the car was $20,500. Was is the cost with the markup?

• $22,500

• $21,525

• $22,575

• $21,225

Calculating Tip or Gratuity

Finding cost with Tip in 3 steps

Step One: Turn the Percent into a Decimal (divide by 100)

Step Two: Multiply the Decimal times the Original Cost

Step Three: Add the product to the Original Cost

Multiple Choice

A large family went out to a steak dinner and the bill was $225. The family plans to leave a 20% tip. What is the cost of the meal with the tip included?

• $270

• $220

• $300

• $260

Calculating Tax

Finding the Cost of an item including Tax in 3 steps

Step One: Turn the Percent into a Decimal

Step Two: Multiply the Decimal times the Original Cost

Step Three: Add the product to the Original Cost

Multiple Choice

While walking around an art gallery, you see a painting that catches your eye. The painting costs $200 plus tax. If the tax is 7.25% - what is the cost of the item including tax?

• $217.25

• $215.00

• $220.75

• $214.50

Multiple Choice

CHALLENGE: While shopping at the mall, you purchase a phone case for $20.00 plus a 5% tax. When you get up to the register to pay, you see there is a 15% discount on the item. How much would you pay for the item, including the discount and the tax? (apply the discount first)

• $16.45

• $17.85

• $18.65

• $17.00