Whole Number Estimation

​Estimate - a rough judgment of a number.

​When do I need to estimate?

• To make sure my answer is reasonable.

• When I only need an approximate amount.

• To solve for an amount quickly.

Multiple Select

Which of the following would be a key word for needing an estimate?

• Approximately

• About

• Closest to

• Estimate

How do we estimate?

Use your rounding skills BEFORE you solve!

Four or less, let it rest. Five or more, raise the score!

​A good rule of thumb is to round to the largest place value of the smallest number.​

For example: 5,480 + 367 ----> round to the hundreds place!

Multiple Choice

What place would you round these numbers to before subtracting?

789,648 - 54,902

• Hundred thousands

• Ten thousands

• Thousands

• Hundreds

​Let's look at this word problem.

​Two local elementary schools are raising money for holiday toys for families in Augusta County. Clymore raised $11,037. Riverheads raised $9,735. About how much more did Clymore raise than Riverheads?

​

What key word do you see? How should we solve?​

​

Multiple Choice

Two local elementary schools are raising money for holiday toys for families in Augusta County. Clymore raised $11,037. Riverheads raised $9,735. About how much more did Clymore raise than Riverheads?

• $1,302

• $1,000

• $21,000

• $20,772

Poll

1,653 + 732

Jordan says that the best way to

estimate this sum is to round to the

nearest hundred. Joy says the best way to

estimate is to round to the nearest

thousand. Who is correct? Be ready to explain.

• Jordan

• Joy

Multiple Choice

Sam needs $325 for the new bike he wants

to purchase. So far, he has saved $73.

About how much more money does Sam

need to save?

• $398

• $400

• $252

• $260

Multiple Choice

Jack ran 826 miles last year.

Jason ran 1,052 miles last year.

About how many more miles

would Jack have needed to run to

match Jason’s distance?

• 226 miles

• 300 miles

• 1,878

• 1,900

Multiple Choice

Jamie earned $462 mowing lawns

over the summer. Then, she made

$66 by selling lemonade. About how

much money did she make all

together over the summer?

• $390

• $396

• $530

• $528