Gap & Difference: If Cody gave Paul 7 magnets, he would have 3/4 as many as Paul. If Cody...

[GWlele]

1.8 Gap and Difference

5. Cody and Paul had some button magnets. If Cody gave Paul 7 button magnets, he would have 3/4 as many button magnets as Paul. If Cody gave Paul 27 button magnets, he would have 1/3 as many button magnets as Paul. How many button magnets did Code have?

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How to do this with drawing diagrams.
Primary 5 math

 

[Steven G]

Hi,
What have you tried? Can you please show us where you are stuck? Thanks.

 

[GWlele]

I don’t know how to do it

 

[GWlele]

Answer given is 55 but I don’t know how to get it

 

[Dr.Peterson]

View attachment 11486

How to do this with drawing diagrams.
Primary 5 math

One reason we want to see some work (besides the fact that it is requested in our submission guidelines) is that seeing even a poor attempt can give us a much better idea of what you have been learning, and what method you should be able to understand. You might even send us a picture of an example your were given showing what sort of diagrams are expected.

The kind of diagram I think of uses a strip to represent each quantity. We might draw a pair of strips, one 3/4 as long as the other to represent the amounts after the first trade, and then mark them up to show each person's original amount, something like this:

+-------+-------+-------+....
| Cody                  | 7 :
+-------+-------+-------+....
+-------+-------+-------+-------+
| Paul                      : 7 |
+-------+-------+-------+-------+

If that looks anything like what you are learning to do, please add a picture of the second fact, and see what you can do with it. If not, show me a picture of some other idea (maybe a picture of something hand-drawn, rather than done as I did this one).

 

[Dr.Peterson]

I want to add two things. First, I searched for the phrase "gap and difference" and found some explanations of a method like what I suggested; some are as complex as this particular problem, though many are simpler. I'm not sure I could figure out what you are expected to do without having seen someone do it.

Second, algebra is a lot easier!

 

[GWlele]

I understand now. Thank you!