Is it 3 am I right
No. The denominators of the question are 3 and 4. What we need to do is convert those fractions so that the denominator is
the same. If we make the second one 3 then it will be difficult to work out (1/4) in thirds.
The best thing to do is get them into a form where they are (something / 12)
I got that number from 3 x 4 = 12
To get (2/3) in the form (something / 12) multiply top and bottom by 4.
To get (1/4) in the form (something / 12) multiply top and bottom by 3.
Last edited by SteveB (2013-04-22 01:24:18)
Hi so is it 3/12 & then. 6/4 am I right?
That is not quite right, but you are getting there. (3/12) is one of the fractions, but the other is wrong. Try again ?
Hint: (1/4) = (3/12)
(2/3) = ????
Last edited by SteveB (2013-04-22 01:28:32)
Is it 6/8 am I right?
No that is not correct. Try again ?
Is it 8/6 am I right?
No the correct answer was that (2/3) = (8/12)
Remember that the other fraction was (3/12). So what is the answer to the original question ?
I am finding this hard to do?
(2/3) + (1/4) = (8/12) + (3/12) = ????
The denominators are now equal. The numerators can now just be added.
Do not add the denominators though.
Last edited by SteveB (2013-04-22 01:40:23)
Is it 11/12 am I right?
Yes that is correct. Now let us go back to Q2.
This was (1/5) + (1/3)
What would be a good denominator to use ?
Is the denominator 5 & 3 am I right?
We need to get the denominators to be same. How could we do that ?
Is it 3x5 =15
So what is (1/5) in fifteenths ?
What is (1/3) in fifteenths ?
Not sure what to do?
(1 / 5 ) = (3 / 15)
The reason for that is that I have multiplied top and bottom by the same number.
In general it is possible to multiply the numerator and denominator by the same number and the fraction is still the same.
You could try drawing a diagram to show this. Let us say you had a square. You divide it into 5 bits which are equal in size.
That represents (1/5) now try dividing the square so that each of the five equal bits are divided into 3 bits.
You can use this to prove that (1/5) = (3/15)
What is (1/3) equal to ?
Last edited by SteveB (2013-04-22 02:01:25)
I could make up an image file to illustrate the division into 3 and 5 and 15, but it will take about 10 minutes to set up.
Do you want to just take my word for it or would you like an illustration ?
Could you do an illustration for me please
Right hopefully the image will display alright.
I have drawn a rectangle. Imagine that the whole of the big rectangle represents the number 1
Now imagine that we have divided this big rectangle into 5 equal bits. Each of these is (1/5).
Now imagine that we have divided this big rectangle into 3 equal bits. Each of these is (1/3).
The very small bits made by dividing the big rectangle into 15 bits are each (1/15)
The fraction (1/5) is really 3 of the very small bits so (3/15)
The fraction (1/3) is really 5 of the very small bits so (5/15)
So is the answer 3/15 + 5/15 = 8/15 am I right?
Do you want to have a go at Q3 ?
It was (1/3) + (5/6)
The answer is greater than one here, but the principle is the same.
I have /18 am I right?