Adding and Subtracting Mixed Numbers with the Same
Now lets consider how to add and subtract mixed
numbers with the same denominator. We start with
Suppose, for instance, that we want to add . Lets draw a diagram to represent
We can rearrange the elements of the diagram by combining the
whole numbers and the fractions separately.
This diagram shows that the sum is .
Note that we can also write and solve this problem vertically.
Similarly, we can subtract mixed numbers that have the same
Can you explain how the preceding diagrams confirm this
To Add (or Subtract) Mixed Numbers That Have the Same
- add (or subtract) the fractions, ¦ add (or subtract) the
whole numbers, and
- write the answer in simplest form.
Our answer is .
Find the sum of .
We set up the problem vertically.
Because . Therefore the difference is .
The value of stock shares is normally expressed in dollars as
a mixed number or fraction. Suppose that one morning the stock of
a certain company opened at a price of per share. By the end of the day, the
price had risen by . What was the price of the stock per
share by the end of the day?
The price of the stock rose by so we must add and .
At closing, then, the price of the stock was per share.
A movie lasts hours. After an hour-and-a-quarter has
passed, how much longer will the movie run?
This question asks us to subtract from
So there is still an hour-and-a-half of the movie to see.