Transcript General School Presentation

The Language of Fractions
Numerator
The numerator is the number, or expression, on the
TOP of the fraction.
3
4
Numerator
Denominator
The denominator is located
down on the bottom of the fraction.
3
4
Denominator
Remember: zero can never be there!
Parts of a whole
The top of the fraction are the parts that we’re
interested in.
The bottom of the fraction is the total.
“I got 19 of the 20 problems right.”
19
20
Proper Fractions
Proper fractions – top is smaller than the bottom.
3
4
Sort of like a
snowman!
Proper Fractions
All proper fractions are less than 1.
(a piece of the pie)
Improper Fractions
Improper fractions – top is bigger than the bottom.
7
3
Sort of like a
bodybuilder.
Improper Fractions
Improper fractions are all bigger than 1.
They can be written as mixed numbers.
2
7
1
 3 7 remainder 1  2
3
3
Remember: the fraction bar is a division sign!
Mixed Numbers
A mixed number is the sum of a whole number and a
fraction.
1
1
2  2
3
3
Mixed Numbers
Any mixed number can be written as an improper
fraction.
1 2  3 1 6 1 7
2 


3
3
3
3
Simplified fractions
A fraction is in lowest terms when the numerator
and denominator have no common factors.
12 2  2  3 2  2 4



15
5
5
3 5
Simplified fractions
It’s easiest to see what you’re doing if you break
each number into prime factors.
12 2  2  3 2  2 4



15
5
5
3 5
You may cancel any matching numbers on the top and
bottom.
Equal fractions
Equal fractions have equal cross-products.
5 1

10 2
10
=
10
Product means multiply ~ cross-product means multiply
across.
This is a good way to check if you reduced correctly.
Remember your terms
Numerator
Denominator
Proper fraction
Improper fraction
Mixed number
Simplified fractions