% proportion, TTD, % of change

Front

What is a percent?

Back

A percent is a ratio expressed as a fraction of 100. It represents a part of a whole.

Front

How do you calculate a percentage of a number?

Back

To calculate a percentage of a number, multiply the number by the percentage (in decimal form). For example, to find 25% of 200, calculate 200 x 0.25 = 50.

Front

What does 'percent increase' mean?

Back

Percent increase measures how much a quantity has grown compared to its original amount, expressed as a percentage.

Front

What does 'percent decrease' mean?

Back

Percent decrease measures how much a quantity has reduced compared to its original amount, expressed as a percentage.

Front

How do you find the percent of change?

Back

Percent of change = (New Value - Original Value) / Original Value x 100.

Front

If an item costs $50 and is on sale for $40, what is the percent decrease?

Back

Percent decrease = (50 - 40) / 50 x 100 = 20%.

Front

What is the formula to find the original price after a discount?

Back

Original Price = Sale Price / (1 - Discount Rate). For example, if an item is $30 after a 25% discount, the original price is $30 / (1 - 0.25) = $40.

Front

If 20% of a class of 30 students are absent, how many students are absent?

Back

Number of absent students = 30 x 0.20 = 6 students.

Front

What is the relationship between fractions and percentages?

Back

Fractions can be converted to percentages by multiplying by 100. For example, 1/4 = 0.25 x 100 = 25%.

Front

How do you determine the total number of items if you know the percentage of a part?

Back

Total = Part / (Percentage in decimal form). For example, if 30% of a total is 15, then Total = 15 / 0.30 = 50.