Algebra Know-It-ALL

96 Decimal Fractions

Start at the decimal point

The “cornerstone” on which any decimal numeral is “built” is the decimal point. It looks like

an ordinary period (.). Digits for positive powers of 10 are written to the left of the decimal

point. Digits for negative powers of 10 are written to the right of the point.

Consider the decimal numeral 362.7735. Let’s break it down. Starting at the decimal

point and working toward the left:

(2 × 100 )+ (6 × 101 )+ (3 × 102 )= 2 + 60 + 300 = 362

105 100,000

(^104) 10,000
103 1,000
102 100
10
1
10
100 1
1/10
1/100
1/1,000
1/10,000
1/100,000
10 –1
10 –2
10 –3
10 –4
10 –5
One order
of magnitude
Three orders
of magnitude
Continues forever!
Continues forever!
Figure 7-1 This is part of the
positive rational
number line, showing
values from 100,000
down to 1/100,000.
The powers of 10
range from 5 down
to −5.