Rounding Numbers

70 80

7477

600 700

630

660

Today we will round numbers

6.C.2.aDetermine the reasonableness of sums and differences

Maryland Student Technology Standard:

3.A.1.a Explore and use teacher-selected technology tools, including software and hardware, to learn content or reinforce skills.

The Rule

Look at the number to the right of the rounding number. If that number is 0, 1, 2, 3, or 4, do not change the rounding number. All the numbers on the right side of the rounding number will become 0.

Round 64 to the nearest 10.

Look at the number to the right of the tens place.

Since the number is 4, leave the 6 as it is and change the 4 to 0.

60

The Rule

If the number to the right of the rounding number is 5, 6, 7, 8, or 9, the rounding number rounds up one number. All the numbers to the right of the rounding number become 0.

Round 270 to the nearest 100.

Look at the number to the right of the hundreds place.

Since the number is 7, round up the 2 and make it 3. Then make the other two numbers 0.

300

60 70

65

6162

63

64 66

67

68

69

Rounding to the Nearest 10

300400

350

310320

330

340 360

370

380

390

Rounding to the Nearest 100

Now it’s your turn!

Round 37 to the nearest 10.

A. 30B. 40C. 35D. 25

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Round 23 to the nearest 10.

A. 20B. 25C. 30D. 35

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Round 670 to the nearest 100.

A. 500B. 600C. 650D. 700

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Round 734 to the nearest 100.

A. 600B. 750C. 800D. 700

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28 students are in Mrs. Smith’s class. About how many students are in her class?

A. 20B. 30C. 40D. 50

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There are 132 pencils in the box. About how many pencils are in the box?

A. 100B. 200C. 300D. 50

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