Addition and Subtraction of Decimals
I. Addition of Decimals
Adding decimals is very similar to adding whole numbers except with a few extra technical details
and bookkeeping. Recall that decimals are just fractions. We add fractions by adding the whole
n
Division of Decimals
I. Dividing a Decimal by a Whole Number
Dividing a decimal by a whole number is similar to dividing whole numbers. One must only be
sure to line up the decimal point of the dividend with that of the quotient.
Example
Divide
143.22 6
S
Applications
I. Strategies For Solving Application Problems
Application problems, a.k.a. word problems or story problems, traditional pose the greatest
challenge to math students. We must keep in mind, however, that other then just enjoying math as
a beau
Applied Problems Involving Fractions
We will follow the same method from 181A to solve applied problems that involve fractions.
Example
The width of a piece of paper is 8 inches. If you want the left and right margins to be 2/3 inches, what
is the width o
Addition and Subtraction of Fractions
I. Adding and Subtracting Fractions With a Common Denominator
No matter how tempting it may be, we can only perform addition and subtraction of fractions
when the denominators are the same.
When the denominators are t
Combining Mixed Numbers and Order of Operations
I. Adding Mixed Numbers
In the last section we learned how to add and subtract two fractions.
If we have two mixed numbers to add, we can just add the whole number parts and then add the
fraction parts.
Exam
The Least Common Denominator
I. The Least Common Multiple
A multiple of a number is a whole number times that number. For example, some multiples of 6
are
6, 12, 18, 24, 30, and 36
If two numbers are given then a common multiple of the two numbers is a nu
Multiplication of Decimals
I. General Multiplication of Decimals
The rules for multiplication of decimals come from the rules of multiplying fractions. Consider
the product
0.02 x 0.013
in fraction form this is
2
13
x
26
=
100
1000
= 0.00026
100000
Notice
Understanding Fractions
I. Definitions
In module A, all the numbers that we encountered were whole numbers. Although the whole
numbers are important, they only tell part of the story. Module B is the study of fractions which are
defined as parts of the wh
Simplifying Fractions
I. Writing a Number as a Product of Primes
We call a whole number greater than one prime if it cannot be divided evenly except by itself and
one. For example the number 7 is prime but the number 6 is not, because
6 = 2x3
A number tha
Square Roots
I. Definition of the Square Root
Recall how we defined exponents, especially with exponent 2. Some examples are
32 = 3 x 3 = 9
102 = 10 x 10 = 100
52 = 5 x 5 = 25
Also recall that the inverse of addition is subtraction and the inverse of mult