7th Grade Christmas Break Review

Front

What is sales tax?

Back

Sales tax is a percentage of the sale price added to the cost of a product or service, collected by the seller and paid to the government.

Front

How do you calculate the total cost with sales tax?

Back

Total Cost = Price + (Price × Sales Tax Rate). For example, for a price of $2.75 and a tax rate of 5%, Total Cost = $2.75 + ($2.75 × 0.05) = $2.89.

Front

What does it mean to solve for x in an equation?

Back

Solving for x means finding the value of x that makes the equation true.

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal.

Front

How do you solve a proportion?

Back

To solve a proportion, cross-multiply and then divide. For example, if a/b = c/d, then ad = bc.

Front

What is the formula to find a percentage of a number?

Back

Percentage of a number = (Percentage Rate / 100) × Number.

Front

How do you find what number a percentage represents?

Back

To find what number a percentage represents, use the formula: Number = (Part / Percentage Rate) × 100.

Front

What is the formula for calculating a percentage increase?

Back

Percentage Increase = [(New Value - Original Value) / Original Value] × 100.

Front

What is the formula for calculating a percentage decrease?

Back

Percentage Decrease = [(Original Value - New Value) / Original Value] × 100.

Front

What is 98% of a number?

Back

To find 98% of a number, multiply the number by 0.98.