The 2 “conceptual” methods of division
Sharing (Way 1) vs
Measurement (Way 2)
Let’s say I have the
problem: .I can do this in 2 ways:
Way #1: “Sharing”
1) I know the number of
groups or people to share with: it is the divisor 3.
Share with 3 people the 12 items*-- First give them each one….
Then give them each
another, and so on
* * * * *
Until all 12 items have
been given away:
2)The answer (remember we just used the sharing method)
is the group size- 4.
Way 2: “Measurement”
1) Measure out 3 items at
a time- this is the group size. We do
not know how many groups will be formed (i.e. how many people we will share
with). Do this until no items are
left.
Here go the first three:
I still have 9 items left.
The next three:
* * *
I still have 6 left.
The next three
I have 3 left to form my final group:
* * *
2) To finish up, I ask:
how many groups were formed? I can see
that 4 groups were formed so 12/3 is 4.
Table: differences between
sharing and measurement for a divided by
b
|
Group size |
Number of groups |
Sharing |
Unknown to start.
Whatever it is after you share the dividend (evenly) of a items amongst your b groups is the answer. The number of the things in each group is
the answer to the division problem. |
You know it- use the Divisor b as the number of groups and then
share your pieces |
Measurement |
You know it- use the Divisor b . Distribute the pieces by measuring them out
evenly into groups of size b until
they are all gone. |
Unknown to start. After you measure out all the pieces evenly , look at how many groups you
have. The number of groups you have is the answer to the division problem. |
One more try:
With sharing, you start with knowing how many people or groups you want to share with and then give out pieces and ask “how many pieces does each group get?”
With measurement, you start with knowing how many you want in a group and ask “how many groups will be formed?”