Estimating Sums and Differences

Front

What is estimating in mathematics?

Back

Estimating is the process of finding an approximate value that is close to the actual value, often by rounding numbers.

Front

What does it mean to round a number to the nearest hundred?

Back

Rounding to the nearest hundred means adjusting a number to the closest multiple of 100.

Front

If you round 382 to the nearest hundred, what is the result?

Back

400

Front

How do you estimate the sum of 1,820 and 1,932?

Back

Round 1,820 to 1,800 and 1,932 to 1,900, then add: 1,800 + 1,900 = 3,700.

Front

What is the estimated total of 1,820 and 1,932 when rounded to the nearest thousand?

Back

4,000

Front

How do you find the difference between two rounded numbers?

Back

Round each number to the nearest hundred or thousand, then subtract the smaller from the larger.

Front

If Eastfield college has 1,537 students and Richland college has 2,785, how do you estimate the difference in students?

Back

Round 1,537 to 1,500 and 2,785 to 2,800. Then subtract: 2,800 - 1,500 = 1,300.

Front

What is the estimated total distance Mr. Smith drove in August and September?

Back

Round 1,380 to 1,400 and 656 to 700. Then add: 1,400 + 700 = 2,100.

Front

How do you estimate the total number of students from three grades?

Back

Round each grade's number of students to the nearest thousand, then add them together.

Front

If 7th graders are 4,945, 8th graders are 5,623, and 9th graders are 1,989, what is the estimated total number of students?

Back

Round to 5,000, 6,000, and 2,000 respectively. Then add: 5,000 + 6,000 + 2,000 = 13,000.