Place Value And Forms Of Numbers (Page 3 of 4) in pdf

Place Value And Forms Of Numbers Page 3

Step 3: Look at the digit to the right of the underlined digit. If that digit is 0, 1, 2, 3, or 4,

keep the underlined digit the same. If the digit is 5, 6, 7, 8 or 9, round up by increasing

the underlined digit by one. Example: 1,689 The 6 has an 8 beside it so I should round

the 6 up to 7.

Step 4: Change all of the digits to the right of the underlined place to zero. Example:

1,689 rounds to 1,700

Another way to think about it:

 1,689 comes between 1,600 and 1,700. It is closer to 1,700 so it rounds to 1,700. (1,650

is halfway between 1,600 and 1,700 so all numbers from 1,650 to 1,700 would round to

1,700.)

If the number that is rounding up is a 9…….

 Example: 2,951 to the nearest hundred – There is a 5 to the right of the hundreds place

which is 9. When I increase the 9, I cannot write a ten in a single place value. You must

increase the place value to the left of the underlined number….so the 2 becomes a 3.

The answer is 3,000.

Practice problems:

12.)

Round to the nearest thousands place: 345,820 __________________

13.)

Round to the nearest hundred thousands place: 345,820 __________________

14.)

Round to the nearest tens place: 2,396 _________________

Estimating Whole Numbers:

 Estimation is used to create a problem that we can solve mentally. You should round to

the place value that is suggested. If you aren’t told what to round to, you should round

to the place value that allows you to solve the problem easily. You should never actually

solve the problem unless the directions tell you to do that. Remember: Estimation is

something that you should be able to use without a calculator or paper/pencil.

Practice problems:

15.)

I am planning to purchase a book for $12.95, a calculator for $29.95, and a pack

of pens for $5.75. About how much will my bill be when I check out? (Do not allow for

tax.) ___________________________

16.)

Round each number to the nearest hundred: 465 + 319 = ___________

17.)

Round each number to the nearest thousand: 3,932 – 2,103 = _____________

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