6.2
Operations on Decimals
Addition
and Subtraction
Rename
as fractional equivalent and get common denominator.
7.812
+ 14.07 + 17
54.03
- 7.154
Traditional
Algorithm - "line up the decimal points"
|
#3 |
#19 |
Multiply
Decimals
Convert
to fractions -
4.01 ´ 6.2
0.04 ´ 0.003
Traditional Algorithm - multiply like "whole
numbers" and count total number of decimal places.
Special Case
If
multiply by 10, 100, 1000, …. (i.e. a
power of 10)
Divide
Decimals
.96 ¸ 3
0.96 ¸ 0.03
9.6 ¸ 0.003
Traditional Algorithm "move decimal point of divisor all the
way to the right, and move the other the same number of places"
#7
Mental
Computation pg 308
Rounding
Decimals
8.3546 to the nearest tenth, …..thousandth ……. Whole number …….hundredths
#78
Assignment: 6.2; pg. 311; 1, 2, 4 6a, 8r, 10r, 11, 14,
18, 20, 21, 22