# Rounding - Michigan State University Creator: Jamin Jones Class CEP: 811 Date: October 29, 2012 Rounding whole numbers and decimals Objectives You will be able to 1. Understand place value up to the tenths and hundredths 2. Round numbers to the nearest tenth and hundredth Core standard:OBJ05CCMA07: Use place value

understanding to round decimals to any place. It is the common core curriculum standard for 5th grade students. Road Map Part One: Round numbers to the nearest tens Round numbers to the nearest hundreds Part Two: Identify tenths place Identify hundredths place Part Three: Round to the nearest tenths place

Key Vocabulary Round - To replace a number with a number that tells about how many. About - Around or close to.

Part 1 Why do we round? 1. When we round, we change a number into another number that it is close to. 2. Rounding numbers is a good way to estimate about how much you have. Rounding rule 5 is in the middle of 0 and 10.

0 1 2 3 4 5

6 When rounding we have to decide if we are going to round up or down. Placement on a the number line can helps us see where to round. 7 8 9 10

Rounding rule 5 and above give it a shove. 0 1 2 3 4

5 6 7 8 9 10

Why do we round? 4 or below leave it alone. 0 1 2 3 4

5 6 7 8 9 10

Rules Look at the number before 4 and below leave it alone 5 and above give it a shove Make everything after it a zero Rounding to the Nearest Ten

26 Click on the number in the tens place. Great Job!!! 26 ones tens Try again. Remember place value order.

3 5 tens ones When rounding we look at the number before the 10. 26 If it is 5 and above you give the tens place a shove.

26 The 2 becomes a 3 and the 6 becomes a 0. 30 26 rounds to 30

Lets try another 32 Click on the number in the tens place. Great Job!!! 32 ones tens Try again.

Remember place value order. 3 5 tens ones Lets try another 32 Shove

The 2 is below 5. Is it going to shove the 3 or leave it alone? Leave Great Job!!! 4 and below leave it alone Try again. Remember the

rule. -5 and above give it a shove -4 and below leave it alone Lets try another 30 The 3 stays the same and the 2 becomes a 0. Another way

10 11 12 13 14 15 16

17 Picture the number on a number line and look for the number it is closest to. 18 19 20 Another way

10 11 12 13 14 15

16 17 18 If you were to find 17 on a number line, would it be closer to 10 or 20? 10 20

19 20 Try again. Remember the rule. 17 is 7 away from 10, but only 3 away from 20. Great Job!!!

17 is only 3 away from 20. Lets Practice Rounds to 38 30 or 40

53 50 or 60 16 10 or

20 44 40 or 50 Great Job!!!

38 rounds up to 40 Try again. Remember the rule. If the ones place is: -5 and above give the tens a shove -4 and below leave the tens alone Great Job!!! 53 rounds down to 50

Try again. Remember the rule. If the ones place is: -5 and above give the tens a shove -4 and below leave the tens alone Great Job!!! 16 rounds up to 20.

Try again. Remember the rule. If the ones place is: -5 and above give the tens a shove -4 and below leave the tens alone Great Job!!! 44 rounds down to 40. Try again.

Remember the rule. If the ones place is: -5 and above give the tens a shove -4 and below leave the tens alone Rounding to the Nearest Hundred 134 Which number is in the hundreds place?

Great Job!!! 134 hundreds ones tens Try again. Remember place value.

1 5 3 hundreds tens ones Rounding to the Nearest Hundred 134 Use the first number to

the right of the hundreds place to decide if you round up or down. Rounding to the Nearest Hundred 134 Shove Is the 3 going to give the hundreds column a shove or leave it alone?

Leave Try again. Remember the rule. If the ones place is: -5 and above give the tens a shove -4 and below leave the tens alone Great Job!!!

The one in 134 will be left alone. Rounding to the Nearest Hundred 100 134 rounds to Everything else becomes a zero.

100 Another way 100 110 120 130 140 150

160 170 Picture a number on the number line between 2 hundreds. Which is it closest to? 180 190 200 Another way

100 110 120 130 140 150 160 170

180 190 200 Would 131 round to 100 or 200? 100 200 Try again. Remember the rule.

If the ones place is: -5 and above in the tens gives the hundreds a shove -4 and below in the tens leave the hundreds alone Great Job!!! 174 will round up to 200. Lets practice Rounds to

174 100 223 200 or 300 562

500 or 600 or 200 Great Job!!!

174 will round up to 200. Try again. Remember the rule. If the ones place is: -5 and above give the hundreds a shove -4 and below leave the hundreds alone Great Job!!! 223 will round down to 200.

Great Job!!! 562 will round up to 600. Place Value Part two Hundreds Tens Ones Decimal There is a pattern with place value that

starts from the ones and moves out. Tenths Hundredths Place Value Hundreds Tens Ones Decimal

Tenths Hundredths You start in the ones and move out. Click on the arrow to follow the pattern. Place Value Hundreds Tens Ones

Decimal Tenths Hundredths Next comes the tenths on one side. Click on the arrow to follow the pattern. Place Value Hundreds Tens

Ones Decimal Tenths Hundredths And the tenths on the other side. Click on the arrow to follow the pattern.

Place Value Hundreds Tens Ones Decimal Tenths Hundredths Next comes hundreds.

Click on the arrow to follow the pattern. Place Value Hundreds Tens Ones Decimal Tenths Hundredths

And then hundredths on the other side. Place Value Hundreds Tens Ones Decimal Tenths Hundredths

The major difference between the two sides is that one side has a -th on the end and is a smaller value. Recognizing tenths and hundreds 34.67 124.35 17.1 2.89 57.21

Click on the number below that correctly answers the question 34.67 124.35 17.1 2.89 Find the numbers with a 6 in the tenths.

57.21 Try again. Remember the place value chart. Hundreds Tens Ones Decimal

Tenths Hundredths ! ! ! b o J t a

Gre Tens Ones Decimal Tenths Hundredths 3

4 . 6 7 Click on the number below that correctly answers the question 34.67 124.35

17.1 2.89 Find the numbers with a 1 in the tenths. 57.21 Try again. Remember the

place value chart. Hundreds Tens Ones Decimal Tenths Hundredths

J t a e r G ! ! ! b o

Tens Ones Decimal Tenths 1 7 .

1 Click on the number below that correctly answers the question 34.67 124.35 17.1 2.89 Find the numbers with

a 1 in the hundredths. 57.21 Try again. Remember the place value chart. Hundreds Tens Ones

Decimal Tenths Hundredths !! ! b o J Great

Tens Ones Decimal Tenths Hundredths 5

7 . 2 1 Click on the number below that correctly answers the question 34.67 124.35 17.1

2.89 Find the numbers with a 5 in the hundredths. 57.21 Try again. Remember the place value

chart. Hundreds Tens Ones Decimal Tenths Hundredths Great Job!!!

Hundreds Tens Ones Decimal Tenths Hundredths

1 2 4 . 3 5 .

Click on the number below that correctly answers the question 34.67 124.35 17.1 2.89 Find the numbers with a 8 in the tenths.

57.21 Try again. Remember the place value chart. Hundreds Tens Ones Decimal

Tenths Hundredths Gre Ones Decimal Tenths

Hundredths 2 . 8 9 at J ob!

Click on the number below that correctly answers the question 34.67 124.35 17.1 2.89 Find the numbers with a 7 in the hundredths.

57.21 Try again. Remember the place value chart. Hundreds Tens Ones Decimal

Tenths Hundredths Gre Ones Decimal Tenths Hundredths

2 . 8 9 at J ob! Rounding Numbers to the

nearest tenth We learned before that you round numbers to estimate how much we have. We can round numbers to figure out approximately how much we owe for a bill. Rounding Numbers to the nearest tenth When rounding to the nearest tenth it is like rounding to the nearest 10 cents in money.

If you dont have exact change you can round to find how much you will pay. Rounding Numbers to the nearest tenth How do we do this? Just like with rounding to the nearest ten and hundred. Rounding Numbers to the nearest tenth Step 1: 1.

2. 3. 4. Look at the number to the right. Is it a 5 and above or a 4 and below Make the change to the correct place Everything else after the number being changed becomes a zero Lets Try 125.45

Which number is in the tenths place? Try again. Remember the place value chart. Hundreds Tens Ones Decimal

Tenths Hundredths ! ! ! b o J t a

Gre Hundreds Tens Ones Decimal Tenths Hundredths 1

5 . 4 5 2 Will the 4 be shoved up or

left the same? 125.45 Shove Leave Try again. Remember the rule. -5 and above give it a shove -4 and below leave it alone

Great Job!!! 4 and below leave it alone 125.50 4 is shoved up to 5 and everything after it becomes a zero. Round to the nearest tenth.

51.12 Which number is in the tenths? Try again. Remember the rule. -5 and above give it a shove -4 and below leave it alone G o

J t a re ! ! ! b Tens Ones

Decimal Tenths Hundredths 5 1 .

1 2 Will the one be left alone or give a shove? 51.12 Shove Leave

Try again. Remember the rule. -5 and above give it a shove -4 and below leave it alone Great Job!!! 4 and below leave it alone Click on the number below that correctly rounds each number to the nearest tenth.

Rounds to 124.35 124.30 or 124.40 17.12 17.10

or 17.20 34.67 34.60 or 34.70

Try again. Remember the rule. -5 and above give it a shove -4 and below leave it alone Great Job!!! 5 and above, give it a shove Great Job!!!

4 and below leave it alone Great Job!!! 5 and above give it a shove You have completed parts 1,2, and 3 of rounding whole numbers and decimals. Credits Created by: Jamin Jones