math help

What is 9/48 + 4/5?

What is 9/48 + 4/5?

This is how we add

9
48
+
4
5

Step 1

Of course, you can't add two fractions if the denominators (bottom numbers) don't match. To get a common denominator, multiply the denominators together. Then we fix the numerators by multiplying each one by their other term's denominator.

Now you multiply 9 by 5, and get 45, then we multiply 48 by 5 and get 240.

9/48 times 5

Do the same for the second term. We multiply 4 by 48, and get 192, then multiply 48 by 5 and get 240.

4/5 times 48

The problem now has new fractions to add:

45
240
+
192
240

Step 2

Since our denominators match, we can add the numerators.

45 + 192 = 237

This yields the answer

237
240

Step 3

The last step is to reduce the fraction if we can.

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

Nope! So now we try the next greatest prime number, 3...

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

237
240
÷ 3 =
79
80

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 5...

Nope! So now we try the next greatest prime number, 7...

Nope! So now we try the next greatest prime number, 11...

Nope! So now we try the next greatest prime number, 13...

Nope! So now we try the next greatest prime number, 17...

Nope! So now we try the next greatest prime number, 19...

Nope! So now we try the next greatest prime number, 23...

Nope! So now we try the next greatest prime number, 29...

Nope! So now we try the next greatest prime number, 31...

Nope! So now we try the next greatest prime number, 37...

Nope! So now we try the next greatest prime number, 41...

Nope! So now we try the next greatest prime number, 43...

Nope! So now we try the next greatest prime number, 47...

Nope! So now we try the next greatest prime number, 53...

Nope! So now we try the next greatest prime number, 59...

Nope! So now we try the next greatest prime number, 61...

Nope! So now we try the next greatest prime number, 67...

Nope! So now we try the next greatest prime number, 71...

Nope! So now we try the next greatest prime number, 73...

Nope! So now we try the next greatest prime number, 79...

Nope! So now we try the next greatest prime number, 83...

No good. 83 is larger than 79. So we're done reducing.

There you have it! Here's the final answer to 9/48 + 4/5

9
48
+
4
5
=
79
80
© 2014 Randy Tayler