Definitions
The rule (three words) used when dividing fractions?
KEEP CHANGE FLIP!
If you are dividing a whole number by a fraction you must first do what to the whole number?
Put a 1 underneath it to make it a fraction.
1/2 ÷ 4
1/8
1/2 ÷ 1/3
3/2 = 1 1/2
1 1/2 ÷ 2 3/4
3/2 x 4/11 = 12/22 = 6/11
A fraction that is less than one. The numerator is smaller than the denominator.
Example: 2/5
Proper Fraction
When dividing fractions, what do you do to the first fraction in the problem?
KEEP it the same.
3 ÷ 2/3
9/2 = 4 1/2
3/4 ÷ 2/5
15/8 = 1 7/8
2 2/5 ÷ 1 3/7
12/5 x 7/10 = 84/50 = 42/25 = 1 17/25
A fraction that is greater than one. The numerator is bigger than the denominator.
Example: 13/2
Improper Fraction
When dividing fractions, what do you do to the division sign?
Change it to multiplication.
4 ÷ 1/2
8
4/7 ÷ 2/3
12/14 = 6/7
5 1/2 ÷ 3 2/3
11/2 x 3/11 = 33/22 = 3/2 = 1 1/2
A whole number plus a fraction.
Example: 1 1/4
Mixed Number
When dividing fractions, what must you do to the second fraction in the problem?
Find its reciprocal or flip it
2/3 ÷ 4
2/12 = 1/6
5/9 ÷ 1/2
10/9 = 1 1/9
2 5/8 ÷ 1 1/3
21/8 x 3/4 = 63/32 = 1 31/32
Also know as the multiplicative inverse. Found by flipping the numerator and denominator of a fraction. When a number is multiplied by this, it will equal 1.
Example: 1/2 X 2/1 = 1
Reciprocal
Fractions should always be in this form: ______.
If possible, convert back to a ____________ number?
Simplest
Mixed
9/17 ÷ 3
9/51 = 3/17
3/4 ÷ 7/8
24/28 = 6/7
3 1/3 ÷ 2 2/5
10/3 x 5/12 = 50/36 = 25/18 = 1 7/8