Intermediate Test Prep Math 8 (Grade 5 ) Mixed Numbers

Subtraction of Mixed Numbers
Lesson

In many word problems, it is necessary to subtract Mixed Numbers. In this lesson, we will learn how to subtract them.

	And how do you subtract Mixed Numbers?
Step one:	Find a common denominator for the proper fraction.
Step two:	Ask yourself the question: in the fractions with LIKE denominators, is the top number's numerator greater than the bottom number's numerator? If yes, go to step three, if no, some renaming must be done on the top number (see box below).
Step three:	In the proper fractions, subtract the numerators, and then subtract the whole numbers.
Step Four:	Put the difference in lowest terms.

Let's try some! (We'll start with an easy one!)


The denominators are like, and the first numerator is greater than the second numerator, soooooo......	just subtract the numerators and the whole numbers!

Let's try a more difficult one (with unlike denominators)!


The denominators are unlike, so find the common denominator and the equivalent fractions for that denominator.
The second numerator (4) < the first numerator (9) soooooo...	just subtract the numerators and the whole numbers!

Let's try one where more renaming must occur before you can subtract.


The denominators are like, but the first numerator is less than the second numerator, soooooo......
you have to borrow from the whole number and.....	becomes becomes
Now you can subtract the whole numbers and the numerators

Here's the most difficult one: the denominators are unlike and the first numerator is less than the second one.


Since the denominators are unlike, find the like denominators.	becomes andbecomes
Now the problem looks like this:	but you can't take 12 from 5
So you have to borrow:
and the problem now looks like this:

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