Math Lesson 1
Numbers up to the Millions

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Instruction 1-5

ROUND OFF WHOLE NUMBERS
CA GR4 NS 1.3 & 1.4
Sometimes it is easier to use rounded off numbers. For example it is easier to say about 100 than 98.9. Rounded numbers end with one or more zeroes.

Ask "is 48 closer to 40 or 50?" It is closer to 50, it is about 50.

Ask "if 81 is closer to 80 or 90?" It is closer to 80. It is about 80.

Round off the same way for larger numbers.
Is 1888 closer to 1000 or 2000? 1888 is closer to 2000.

Is 43,556 closer to 40,000, or 50,000? Compare the first two numbers. 43 is closer to 40 than 50. It is 40,000.

"Tricky" numbers are those with 5 as the number that decides. Is 650 closer to 600 or 700? On a number line 650 is half way. Math has a rule for this. When the digit is 5 or greater, round up. When the digit is less than 5, round down.

You may need to estimate to a certain place. Look at the number in the place to the right. Then round. Round 684 to the tens place.

A 4 is right of the tens in the ones place. It rounds to 680.

6423 rounded to the nearest 10 is 6420.
6423 rounded to the nearest hundred is 6400.
Rounded to the nearest thousand, it is 6000.

For another set of examples use 589,457:

Rounded to the nearest 10, it is 589,460.
Rounded to the nearest 100, it is 589,500.
Rounded to the nearest 1000, it is 589,000.
The nearest 10,000 is 590,000.
The nearest 100,000 is 600,000.
You can round it to the nearest million, 1,000,000.

The named estimate place will have the same number of zeros as the number you round to.

Worksheet 1 Rounding to the nearest 10

Worksheet 2 Rounding to the nearest 100

Worksheet 3 Rounding to the nearest 1,000

Worksheet 4 Rounding to the nearest 10,000 and hundred thousand

Worksheet 5 Rounding to the nearest million and ten million

Video Instruction
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