Decimals Review
by Lauren McCluskey
Decimal Models
Tenth
Hundredth
by Christine Berg
Remember that each period has
three place values within the period
671,690,492.36754
by Moncia Yuskaitis
Equivalent Decimals
0.6 or 6 tenths
0.60 or 60 hundredths
by Christine Berg
Use rounding
• When the question asks you
to estimate.
• When you want to know if
your answer is reasonable.
by Monica Yuskaitis
Memorize this Poem
Find your number.
Look right next door.
4 or less just ignore.
5 or more, add 1 more.
by Monica Yuskaitis
Round to the tenths:
 75.86
 75.83
 75.96
 75.835
Find your number.
Look right next door.
4 or less just ignore.
5 or more, add 1 more.
 75.86
is about 75.9
 75.83 is about 75.8
 75.96 is about 76.0
 75.835 is about 75.8
Which is greater:
0.6 or 0.58?
0.6
0.58
by Christine Berg
Which is greater:
0.400 or 0.5?
0.400
0.5
by Christine Berg
Adding or Subtracting Decimals
When adding or subtracting decimals,
line them up!
What is:
1. $7.54 + $3.56?
2. $15.00 - $6.27?
3. $0.75 + $1.25 + $6.79?
4. 75.425 + 3.5005?
5. 98.322 – 7.0545?

Adding or Subtracting Decimals
When adding or subtracting decimals,
line them up!
What is:
1. $7.54 + $3.56 = $11.10
2. $15.00 - $6.27 = $8.73
3. $0.75 + $1.25 + $6.79 = $8.79
4. 75.425 + 3.5005 =78.9255
5. 98.322 – 7.0545 = 91.2675

Multiplying Decimals
Multiplying decimals is counterintuitive.
 What is 0.10 * 6?
 Think about money. 0.10 is a dime,
and you have 6 of them, so how
much do you have? 0.60.

Multiplying Decimals
0.1 * 0.6 =
Multiplying Decimals
0.06
0.1 * 0.6 =
Or… one tenth of 6 tenths is 6 hundredths.
Try it!
1.
2.
3.
2.50 * 0.1 ?
87.655 * 0.001?
125.75 * 1.0?
Try it!
1.
2.
3.
2.50 * 0.1 = 0.250
87.655 * 0.001 = 0.087655
125.75 * 1.0 = 12.575
Dividing Decimals
Dividing decimals can be counter-intuitive.
Dividing a decimal by a decimal can give you a
larger number.
0.6 ÷
0.1=
Or… there are
6 tenths in 0.6.
6
tenths
Try it!
1.
2.
3.
875.25 ÷ 0.01 ?
9218.4 ÷ 0.1?
722.36 ÷ 0.0001?
Try it!
1.
2.
3.
875.25 ÷ 0.01 = 87,525
9218.4 ÷ 0.1 = 92,184
722.36 ÷ 0.0001 = 7,223,600
Credits:

Comparing and Rounding Decimals by
Christine Berg

Math Flash Place Value by Monica
Yuskaitis

Math Flash Rounding by Monica
Yuskaitis