Transcript little italy

Fraction Division
Opposite of Multiplication
The opposite
number:
• Invert
• Called the reciprocal
• 3
4
invert to make
4
3
To Divide
• Invert the second number
• Multiply
2 3 2 4 8
   
5 4 5 3 15
Steps
• Change Whole numbers and mixed
numbers to improper fractions
• Invert the second fraction (the divisor)
and multiply
• Cancel if you can
• Multiply numerator by numerator and
denominator by denominator.
Examples
•
1
2
4
1 2

4 1
1 1

4 2
1 1 1
 
4 2 8
3
1
2
4
5
•
3 11

4 5
3 5

4 11
3 5 15
 
4 11 44
Word Problems
Commutative
•
•
•
•
Multiplication is commutative
3x4 = 4x3
Is division commutative?
NO!
Division
• The order matters
• When working word problems, be
careful what order you write the
problem.
• The thing being split, cut, sorted,
shared, divided, or grouped goes first.
• How many pieces or how big goes
second.
Fran puts 5 1/3 lbs of chocolate
in 2/3 lb containers. How many
containers?
• Chocolate is first as it is split.
• Total divided by How Big is How Many.
1 2 16 3 8 1
5      8
3 3
3 2 1 1
• 8 containers.