M7 UNIT 5 PROPORTIONAL REASONING STUDY GUIDE

Front

What is proportional reasoning?

Back

Proportional reasoning is the ability to compare ratios and understand the relationship between quantities. It involves recognizing that two ratios are equivalent.

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 10% of 70, calculate 70 x 0.10 = 7.

Front

What is the scale factor in a model?

Back

The scale factor is the ratio of the dimensions of the model to the actual dimensions. For example, if 2 inches on a model represents 14 feet, the scale factor is 1:84.

Front

How do you find the actual height of a building from a model?

Back

To find the actual height, multiply the height of the model by the scale factor. For example, if the model is 9 inches high and the scale is 2 inches = 14 feet, the actual height is 9 x (14/2) = 63 feet.

Front

What is 15% of a number?

Back

To find 15% of a number, multiply the number by 0.15. For example, 15% of 550 is 550 x 0.15 = 82.5.

Front

How do you calculate a tip based on a bill amount?

Back

To calculate a tip, multiply the bill amount by the tip percentage (in decimal form). For example, for a $68 bill with a 15% tip, calculate 68 x 0.15 = 10.2, then add this to the bill.

Front

What is the total bill including a tip?

Back

To find the total bill including a tip, add the tip amount to the original bill. For example, if the bill is $68 and the tip is $10.2, the total is $68 + $10.2 = $78.20.

Front

What does it mean for two ratios to be equivalent?

Back

Two ratios are equivalent if they represent the same relationship between quantities. For example, the ratios 1:2 and 2:4 are equivalent.

Front

How do you convert a fraction to a percentage?

Back

To convert a fraction to a percentage, divide the numerator by the denominator and multiply by 100. For example, 1/4 = 0.25 x 100 = 25%.

Front

What is the formula for finding the scale of a model?

Back

The formula for finding the scale of a model is: Scale = Model Size / Actual Size. For example, if a model is 2 inches and the actual size is 14 feet, the scale is 2 inches / 14 feet.