+0  
 
0
1107
2
avatar
Hi everyone,

I have a problem which is very annoying. I struggle with remembering how to solve addition, subtraction, multiplication and division fractions.
I know how to solve them but I forget which rules apply to which ones, does anyone have an easy way to remember the rules for them?

Every time I do fractions I will work out 5 or 6 questions in a row easy and then get stuck with the next 2 or 3 for ages before I figure out
how to do them again, it will save a lot of time and be very helpful if anyone's got like a SOHCAHTOA for trigonometry.
 Jan 29, 2014
 #1
avatar+135 
0
Hello guest!

I like to remember them visually.

Suppose you have half a pie and you add a quarter pie.
Then you get three quarters of a pie.

The trick is to slice the pieces into smaller pieces that have the same size.
In other words, to add 2 fractions, first you have to make the denominators the same, and then you can add them.

1/2 + 1/4 = 2/4 + 1/4 = 3/4

Note that half a pie is the same as 2 pieces of a quarter pie.

Or a little more difficult:

1/2 + 1/3 = 3/6 + 2/6 = 5/6
 Jan 29, 2014
 #2
avatar+118609 
0
Guest:

Hi everyone,

I have a problem which is very annoying. I struggle with remembering how to solve addition, subtraction, multiplication and division fractions.
I know how to solve them but I forget which rules apply to which ones, does anyone have an easy way to remember the rules for them?

Every time I do fractions I will work out 5 or 6 questions in a row easy and then get stuck with the next 2 or 3 for ages before I figure out
how to do them again, it will save a lot of time and be very helpful if anyone's got like a SOHCAHTOA for trigonometry.



I like Serena has got some really good ideas there!

I teach this stuff at my home and my favourite teaching aid is 1 or more empty egg carton and some coloured lego blocks.
Egg cartons have 12 eggs in them.
If you want 1/2 a cartoon then you have to divide the box into 2 equal pieces and put lego blocks in 1 of those peices. That means there will be lego in 6 spaces because that is a half of the carton.
Now say you want 1/12 of a carton. That means you have to divide the carton into 12 peices, thats easy because it held 12 eggs to start with. So 1/12 of the carton will be just one eggs worth.
Now, if you want to add 1/2 + 1/12 You can do it with your carton.
Fill up half the carton with red blocks What is 1/2 the same as? the lego should be in 6 of the 12 holes. That is a 1/2 so 1/2 must be equal to 6/12
Now fill up 1/12 of the carton with blue blocks that means think of think of the carton as 12 bits and put a blue block in 1. That's just like 1 egg.
Now if you want 1/2 + 1/12 you can count the eggs 1/2 was 6 eggs that 6/12 add the other 1/12 and you get 7/12

Once you play with the egg cartons for a while you will understand much better and then it will be much easier to do it without the cartons.

Times and divide are actually easier than plus and minus but i think you should get yourself some egg cartons and have a play first with understanding fractions and with + and -

With an egg carton you can 'play' with 1/2 , 1/3, 1/4, 1/6, 1/12 you can also play with 2/3,3/3,2/4,3/4,4/4,2/6,3/6,etc, 2/12, 3/12 etc See if you can work out which ones are equal.
I would love to hear back from you and you can tell me if it helped.
BUT you have to actually DO IT first.

If you want to play with 10th or 5th or with decimals you can have a different carton and just tear the end two bits off so it fits 10 eggs.
 Jan 30, 2014

3 Online Users

avatar
avatar