math help

What is 72/63 + 5/10?

What is 72/63 + 5/10?

This is how we add

72
63
+
5
10

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 72 by 10, and get 720, then we multiply 63 by 10 and get 630.

72/63 times 10

Do the same for the second term. We multiply 5 by 63, and get 315, then multiply 63 by 10 and get 630.

5/10 times 63

The problem now has new fractions to add:

720
630
+
315
630

Step 2

Since our denominators match, we can add the numerators.

720 + 315 = 1035

The sum we get is

1035
630

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:

1035
630
÷ 3 =
345
210

Let's try dividing by that again...

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

345
210
÷ 3 =
115
70

Let's try dividing by that again...

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

Are both the numerator and the denominator evenly divisible by 5? Yes! So we reduce it:

115
70
÷ 5 =
23
14

Let's try dividing by that again...

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...

No good. 17 is larger than 14. So we're done reducing.

There you have it! Here's the final answer to 72/63 + 5/10

72
63
+
5
10
=
23
14
© 2014 Randy Tayler