Multiplying fractions.

[pompey]

Im retaking gcse maths at and ICT at college, were doing our first module and im fine with most of it parts of it apart from multipying fractions, I dont get the common demenoimater and numerator stuff where u have to find the bottom most common mulitple and multiply to get a fraction then. If i write one out could some1 explain plz. 1 � X 1 � =? It well confusing is multiplying fractions with whole numbers, any help would be appreciated.

[rja211077]

To multiply fractions you simply multiply the tops and multiply the bottoms. i.e. 1/2 x 3/4 = 3/8. if a fraction is mixed ie. whole numbers plus fractions you need to convert to a top-heavy fraction first i.e. 1.5 = 3/2, 1.75 = 7/4. so answer is 21/8 or 2 and 5/8.

[tomd]

Retaking already? http://www.math.com/school/subject1/lessons/S1U4L4GL.html might help, just turn everything into improper fractions first (ie. 1 1/2 to 3/2) and carry on like normal.

[pompey]

still confused as i got an E in gcse maths lol, but i wanna get a C grade, cheers for ur help .laterz

[FP]

I'm not very good at explaining these things rja211077. Perhaps pompey needs to know how to convert whole numbers plus fractions into top-heavy fractions.

[pompey]

rja i dont get how it is 2and 5/8 lol, could u explain

[OBonio]

You only need a common denominator when you add and subtract fractions.

[FP]

pompey, see my reply to you under your heading on food and you will find out something!

[Ouisch]

To convert 1 1/2 to an improper fraction, multiply the denominator by the whole number, then add the numerator. So in this case, you multiply 2 times 1, which equals 2, then add 1, for a total of 3. So your improper fraction is 3/2. Now do the same for 1 3/4....4 times 1 is four, plus 3 equals 7. Your new equation looks like this: 3/2 X 7/4 Now you multiply that like you would any fraction, and your total is 21/8. You now have to reduce your answer so that it looks like a mixed fraction: 2 5/8.

[New Forester]

It might be helpful to think of each whole number as divided up into fractions.  One is therefore two halves, or seven sevenths, or a hundred and thirty nine hundred and thirty ninths.

 

< P>In your example, 1 � is two halves of the one, plus the spare half, making three halves in all.  Your 1 � is four quarters of the one, plus three spare quarters, making seven quarters.

 

You are therefore asking "what is three halves of seven quarters".  This can be done in the same way as any other fraction (and from what you say I think you can do that in the same way you'd do, for example, three fifths of three quarters).

 

Once you've got your answer of 21 eighths, it's just a matter of working out how many whole numbers of eight eighths it contains.

[allan.g0ias]

After all this....... I think the answer lies in the soil...