Add Fractions With Like Denominators

How about this pizza?

pizza cut into 8 pieces

There are 8 pieces, so 1 slice a 1/8 slice of pizza is 1/8 of the pizza.

So a 1/8 slice of pizzaa 1/8 slice of pizzaa 1/8 slice of pizza is 3/8

and a 1/8 slice of pizzaa 1/8 slice of pizzaa 1/8 slice of pizzaa 1/8 slice of pizza is  4/8

Let's add

3/8 + 4/8

a 1/8 slice of pizzaa 1/8 slice of pizzaa 1/8 slice of pizza+a 1/8 slice of pizzaa 1/8 slice of pizzaa 1/8 slice of pizzaa 1/8 slice of pizza

=a 1/8 slice of pizzaa 1/8 slice of pizzaa 1/8 slice of pizzaa 1/8 slice of pizzaa 1/8 slice of pizzaa 1/8 slice of pizzaa 1/8 slice of pizza

=7/8

So 3/8 + 4/8 = 7/8

Did you notice what's happening?

We are just adding the numerators!
(We can ONLY do this when the denominators are the same.)

3/8 + 4/8 = (3+4)/8 = 7/8

Let's do one without pictures:

2/9 + 3/9 = (2+3)/9 = 5/9

Easy!

 

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