Rounding Whole Numbers Lesson

Rounding Whole Numbers

​Rounding numbers is when you round numbers up to a higher number or down to a lower number. You can round to tens, hundreds, thousands, and more. When rounding to a certain place, you need to look at the number to the right of it. If it is 5 or larger, you round to a larger number. If it is 4 or less, the number in the place value you are rounding to rest and digits afterwards change to zero.

​A number line shows numbers in order and can show numbers greater or less than. They also help us see patterns.

​How can a number line help us round numbers?

Benchmark numbers on a number line
are located at the endpoints and show
which number the target number could

round down or up to.

What are benchmark numbers?

If you are rounding the two-digit number

53 to the tens place, what would be
examples of benchmark numbers?

The benchmark numbers would be 50 and 60.

If you are rounding the two-digit number
53 to the tens place, the halfway point
between 50 and 60 is 55. What would

the number 53 round to and why?

Halfway point is 55

Regrouping Poem

Find the place value
Look next door
5 or more, RAISE THE SCORE BY ONE MORE
4 or less, LET IT REST
The digits to the left, stay the same
The digits to the right, zero is your name

If you are rounding the three-digit

number 449 to the nearest hundred,

what would be examples of benchmark

numbers?

The benchmark numbers for 449 when rounding to the nearest hundred are 400 and 500.

If you are rounding the three-digit

number 956 to the nearest ten, what

would be examples of benchmark

numbers?

Multiple Choice

If you are rounding the four-digit number 1,934 to the nearest ten, which number would it round 

to?

• 1,930

• 1,940

• 1,900

• 2,000

Multiple Choice

If you are rounding the five-digit number 21,934 to the nearest thousand,

which number would it round to?

• 21,900

• 21,930

• 21,940

• 22,000