| |
|
| |
Multiply / Divide
Add / Subtract |
|
|
When do you
MULTIPLY / DIVIDE
Multiply:
You multiply when the problem wants a
total and the numbers are the same or when the problem asks for part of
something else.
- Example: There are 5 beads in each envelope. There
are 10 envelops how many beads in all?
5 x 10 ---there are 5 10's and a total is asked
for--
- Example: There is 330 students at the High School. What
is 1/3 of all the students at the School? 1/3
times 330 = 110
- Divide: You divide when the problem wants to
know what one, each, or per is and when the problem asks or implies how many is
inside of something .
- Example:
- How many 1/4's or inside of 3 and 1/2?
- There are 150 marbles in 10 envelopes. How many in
each ( per ) (one) envelope?
- 2.5 ounces of liquid soap are needed for a washer of clothes.
The bottle of soap contains 250 ounces. How many washer
loads can you get from a bottle of soap?
When do you Add /
Subtract
- ADD We add when the problems wants to know a total ( stated or implied)
and the numbers are different.
- SUBTRACT: We subtract when the problem compares, takes away, is a have
and need and wants to know what is the rest.
- Compares----When a problem asks How much more ,--how much less - etc
.
- Take Away . I have so many and someone takes so much away and wants
to know how much is left.
- Have and Need. The recipe calls for 2 and !/2 cups of sugar. Jan has
3/4 cup. How much more sugar does she need?
- What is the rest. When a problem asks or implies what is the rest it
is subtraction. The distance from Homosassa to Invernes is 22 miles. The
distance from Homosassa to Lecanto is 10 miles. What is the distance
from Lecanto to Inverness ( the rest )