Number (order and place value)

Hong Kong

Stage 2

Lesson

To round a number to the nearest $10$10 means to find the $10$10's place value that a number is closest to.

Watch the video below to see some examples of rounding to the nearest $10$10. Can you spot a number that is close to two different $10$10's values? What should you do?

Rounding to the Nearest $10$10

• Find which $10$10 a number is closest to ( a $10$10 is a number like $10$10,$20$20,$30$30,$40$40, … $310$310, $320$320, $330$330, $1530$1530, … and so on)

•If a number is exactly in the middle, round to the higher number.

To round a number to the nearest 100 is similar to rounding to the nearest $10$10. When rounding to the nearest $100$100, find the $100$100's place value that a number is closest to.

Watch some examples and do some practice in the video below. Stay until the end for an extra challenge!

Did you see how similar the rules are for rounding to the nearest $100$100? Read the rules below and compare them to the rules for rounding to the nearest $10$10.

Rounding to the Nearest $100$100

• Find which $100$100 a number is closest to ( a $100$100 is a number like $100$100, $200$200, $300$300, $400$400, … $3100$3100, $3200$3200, $3300$3300, and so on)

•If a number is exactly in the middle, round to the higher number.

Round $54$54 to the nearest ten.

Round $370$370 to the nearest hundred.

Three numbers have been rounded as follows:

$3600$3600 rounds to $3600$3600, $3470$3470 rounds to $3470$3470, and $2887$2887 rounds to $2890$2890.

What have the numbers been rounded to?

The nearest hundred

AThe nearest ten

B