MCA Flashcard: Number Sense #3

Front

What is the speed of sound in meters per second?

Back

Sound travels at a speed of approximately 343 meters per second in air at room temperature.

Front

How do you calculate the time it takes for sound to travel a certain distance?

Back

Time = Distance / Speed. For example, to find how long it takes sound to travel 1,730 meters, use the formula: Time = 1730 m / 343 m/s.

Front

If a student reads a book in a certain number of days, how can you find out how long it would take them to read a different book?

Back

You can use the rate of reading (pages per day) to calculate the time for the new book by dividing the total pages of the new book by the rate.

Front

What does it mean to answer 80% of questions correctly?

Back

It means that if there are 100 questions, the student answered 80 questions correctly.

Front

How do you find the total number of questions on a quiz if you know the number answered correctly and the percentage?

Back

Total Questions = Correct Answers / (Percentage Correct / 100). For example, if 28 questions were answered correctly at 80%, then Total Questions = 28 / 0.8 = 35.

Front

What is the relationship between inches of snow and inches of water?

Back

The relationship can be expressed as a ratio. For example, 36 inches of snow is equivalent to 4.5 inches of water, which can be simplified to find the equivalent water for different amounts of snow.

Front

How do you convert inches of snow to inches of water?

Back

Use the ratio from the known conversion. For example, if 36 inches of snow equals 4.5 inches of water, then for 10 inches of snow, you can set up a proportion to find the equivalent water.

Front

What is a proportion in mathematics?

Back

A proportion is an equation that states that two ratios are equal. For example, if a/b = c/d, then a, b, c, and d are in proportion.

Front

How do you set up a proportion to solve a problem?

Back

Identify the known ratios and set them equal to the unknown ratio. Cross-multiply to solve for the unknown.

Front

What is the formula for calculating the equivalent amount of water from snow?

Back

Equivalent Water = (Inches of Snow / Inches of Snow in Water) * Inches of Water.