Decimal Operations
Line Up
Decimals?
Process
Examples
23.05 + 0.028
change to:
YES!
- Line up decimals
- Annex zeros, if
needed
- Add like whole
numbers
- Drop decimal straight
down into sum
934.6 – 0.34
change to:
YES!
- Line up decimals
- Annex zeros, if
needed
- Subtract like whole
numbers
- Drop decimal straight
down into difference
31.2 x 0.27
NO!
- Multiply like whole
numbers, without
decimals
- Put decimals back in
and count places to
right of each decimal
- Move decimal to left
into product the same
number of places
If NO decimal in
divisor:
- Bring UP decimal from
dividend into quotient
- Divide like whole #s
23.050
+ 0.028
23.078
934.60
- 0.34
934.26
312
x 27
2184
+6240
8424
31.2
0.27
8424
1 place right
+2 places right
= 3 so move
decimal in 3
places to
left:
8.424
20.5 ÷ 5
change to:
5.1
5 20.5
UP
75.3 ÷ 6.25
quotient
divisor dividend
NO!
IF decimal in divisor:
- Move decimal in divisor
to right to create whole
number
- Move decimal in
dividend to right same
number of places
- Bring UP decimal from
dividend into quotient
change to:
6.25 75.3
change to:
12.048
625 7530.000
OVER OVER UP