Download 5.5 Notes

SOL 5.5 Notes
Decimal Operations

Addition and subtraction of decimals is like adding and subtracting whole numbers. The
only thing we MUST remember is to line up the decimals!
Add a 0 here so
you can regroup

To multiply decimals, first multiply them as if they were whole numbers. Then, you must
figure out where to place the decimal in the product. To do this, count the number of places
behind the decimal in the entire problem (both factors.) Then, put the same number of places
behind the decimal in the product. You do not need to line up decimals or place values
when multiplying.

Dividing decimal numbers is like dividing whole numbers. We just need to remember to
bring the decimal straight up to the quotient.
-2 0
35
- 35
0
0

When estimating decimal numbers, round to largest place of the smallest number, then
perform the operation.
23.67 
24.00
2.43 
2.00
+ 11.86  + 12.00
38.00
49.72 
52.41 
+ 10.82 
50.00
50.00
+10.00
110.00
Sample Questions
1. Claire’s sells bracelets for $4.99 each. Michelle bought 4 yellow bracelets and 5 pink bracelets.
How much did Michelle spend at Claire’s?
A
B
C
D
$19.96
$24.95
$44.91
$49.90
2. What is 56.834 – 3.497
A
B
C
D
53.337
53.463
60.331
91.804
3. 56.89 X 45.2 =
A
B
C
D
2,571,428
25,714.28
2,571.428
257.1428
4. Andrew and his two brothers want to put their money together to buy a new gaming system. If
the gaming system costs $168.69, how much money will each boy need to contribute so they put
in equal amounts?
A
B
C
D
$56.23
$84.34
$171.69
$506.07
5.
98.34 + 61.7
A
B
C
D
36.64
92.17
104.51
160.04