# Help with fractions

• May 2nd 2011, 12:58 PM
Kimber
Help with fractions
Can someone please tell me how to explain to a 3rd grader how to find fractions greater than 3/4??
• May 2nd 2011, 01:06 PM
Plato
Quote:

Originally Posted by Kimber
Can someone please tell me how to explain to a 3rd grader how to find fractions greater than 3/4??

Does that third grader know that $\displaystyle \frac{3}{4}=\frac{6}{8}~?$
If so then $\displaystyle \frac{7}{8}$ works.
• May 2nd 2011, 01:17 PM
TheChaz
Quote:

Originally Posted by Plato
Does that third grader know that $\displaystyle \frac{3}{4}=\frac{6}{8}~?$
If so then $\displaystyle \frac{7}{8}$ works.

To add to Plato's reply, we can take $\displaystyle \frac{4}{5}$, which is less than $\displaystyle \frac{5}{6}$, which is less than...

... $\displaystyle \frac{100}{101}$, which is less than... etc.

Any fraction of the form $\displaystyle \frac{n}{n+1}$, where n is a whole number, will get closer and closer to "1.000" as n gets larger.
But you might want to leave that part out of the discussion with the 3rd grader... ;)
• May 2nd 2011, 01:55 PM
Kimber
She really understood it thatnks. For lesser than would it work the same way but substact one?
• May 2nd 2011, 02:01 PM
TheChaz
Quote:

Originally Posted by Kimber
She really understood it thanks. For lesser than would it work the same way but subtract one?

Yes, but you'll run out (at least if you stick to the pattern n/(n +1)) after 1/2. Or maybe 0/1!

What you can do is to increase the denominator (bottom) while leaving the numerator (top) the same.
This would make a bunch of sense to a 3rd grader if you expressed the number of pizza each person got at a party with a fraction...

1/7 means 1 pizza for 7 people.
2/5 means 2 pizzas for 5 people. If we only have 2 pizzas but keep inviting more and more people, we get...
2/20 --> 2 pizzas for 20 people.
2/100 --> 2 pizzas for 100 people...
etc.
Clearly you can tell that each person will only get a bite after increasing the denominator sufficiently!
• May 2nd 2011, 02:07 PM
Kimber
Thats awesome thank you very much she says that makes more sense!!! =^)