1. ## fractuin

fractuin = fraction
What the reason that multiplication of fractions is:
Suppse:
a/b, c/d are fraction.
The product:
(a / b) * (c / d) = ac / bd

2. ## Re: fractuin

The "reason" is simply that it's the correct way!

Try it yourself...use actual fractions...

https://www.mathsisfun.com/fractions...plication.html

3. ## Re: fractuin

One way to look at this is that the denominators of fractions are "units".

If you have 2/3 you have two of these things we call "thirds"- in the same way that is you have "2 meters" you have two of these things we call "meters". Just as if we have a rectangle with width 3 meters and height 20 cm then the rectangle has area 60 "cm-meters" which we would probably convert to either 6000 cm^2 or 0.6 m^2, that is, we multiply the numbers and multiply the units, so 2 thirds time 5 sevenths is 10 "thirds-sevenths" which we would call 10 "twentyfirsts" or 10/21.

4. ## Re: fractuin

You can work it out this way ...

Multiply both sides by b
a * c/d =b * answer
Multiply both sides by d
a * c = b * d * answer
Divide both sides by a
c = (b * d) / a * answer
Divide both sides by c
1 = (b * d) / (a * c) * answer
Multiply both sides by (a * c)
(a * c) = (b * d) * answer
Divide both sides by (b * d)
(a * c)/(b * d) = answer
or....
answer = (a * c)/(b * d)