math help

What is 16/48 + 7/9?

What is 16/48 + 7/9?

This is how we add

16
48
+
7
9

Step 1

We can't add two fractions with different denominators (the bottom number). So you need to get a common denominator - both bottom numbers need to match. To do this, you'll multiply the denominators times each other... but the numerators have to change, too. They get multiplied by the other term's denominator.

So we multiply 16 by 9, and get 144, then we multiply 48 by 9 and get 432.

16/48 times 9

Do the same for the second term. We multiply 7 by 48, and get 336, then multiply 48 by 9 and get 432.

7/9 times 48

So now our fractions look like this:

144
432
+
336
432

Step 2

Since our denominators match, we can add the numerators.

144 + 336 = 480

So the answer is:

480
432

Step 3

Last of all, we need to simplify the fraction, if possible. Can it be reduced to a simpler fraction?

To find out, we try dividing it by 2...

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

480
432
÷ 2 =
240
216

So far so good... let's try to divide by that number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

240
216
÷ 2 =
120
108

So far so good... let's try to divide by that number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

120
108
÷ 2 =
60
54

So far so good... let's try to divide by that number again.

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

60
54
÷ 2 =
30
27

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 3...

Are both the numerator and the denominator evenly divisible by 3? Yes! So we reduce it:

30
27
÷ 3 =
10
9

So far so good... let's try to divide by that number again.

No good. So next you try the next prime number, which is 5...

No good. So next you try the next prime number, which is 7...

No good. So next you try the next prime number, which is 11...

No good. 11 is larger than 10. So we're done reducing.

And we're done! Here's the final answer to 16/48 + 7/9

16
48
+
7
9
=
10
9
© 2014 Randy Tayler