7TH GRADE 6.2: ESTIMATE TO CHECK REASONABLENESS

Front

What is the formula to calculate distance when speed and time are known?

Back

d = rt, where d is distance, r is rate (speed), and t is time.

Front

How far does sound travel in one second?

Back

Sound travels about 1,125.33 feet in a second.

Front

If an engineer hears an explosion 8 seconds after it occurs, how far away is the explosion in feet?

Back

8,000 feet (calculated as 1,125.33 ft/sec * 8 sec).

Front

How far away is the explosion in miles if it is 8,000 feet away?

Back

1.5 miles (since there are 5,280 feet in a mile, 8,000 feet ÷ 5,280 ft/mile = 1.515 miles).

Front

What is the estimated number of vans needed for 305 people if each van can carry 18 people?

Back

15 vans (305 ÷ 20 = 15, estimating 20 people per van for easier calculation).

Front

What is the purpose of estimation in problem-solving?

Back

Estimation helps to quickly assess the reasonableness of an answer without exact calculations.

Front

What does it mean for an answer to be reasonable?

Back

An answer is reasonable if it is logical and falls within a range that makes sense based on the context of the problem.

Front

How can you check the reasonableness of your answer in a math problem?

Back

You can check by estimating the numbers involved and comparing your answer to the estimate.

Front

What is the relationship between feet and miles?

Back

1 mile = 5,280 feet.

Front

If a problem states that sound travels at 1,125.33 ft/sec, how would you estimate the distance for 10 seconds?

Back

Estimate: 1,125 ft/sec * 10 sec = 11,250 feet.