Here's how to add


Step 1We 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 5 by 7, and get 35, then we multiply 12 by 7 and get 84. Do the same for the second term. We multiply 4 by 12, and get 48, then multiply 12 by 7 and get 84. So now our fractions look like this:


Step 2Since our denominators match, we can add the numerators. 35 + 48 = 83 Now we have an answer.


Step 3Last 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... Nope. Try the next prime number, 3... Nope. Try the next prime number, 5... Nope. Try the next prime number, 7... Nope. Try the next prime number, 11... Nope. Try the next prime number, 13... Nope. Try the next prime number, 17... Nope. Try the next prime number, 19... Nope. Try the next prime number, 23... Nope. Try the next prime number, 29... Nope. Try the next prime number, 31... Nope. Try the next prime number, 37... Nope. Try the next prime number, 41... Nope. Try the next prime number, 43... Nope. Try the next prime number, 47... Nope. Try the next prime number, 53... Nope. Try the next prime number, 59... Nope. Try the next prime number, 61... Nope. Try the next prime number, 67... Nope. Try the next prime number, 71... Nope. Try the next prime number, 73... Nope. Try the next prime number, 79... Nope. Try the next prime number, 83... Nope. Try the next prime number, 89... No good. 89 is larger than 83. So we're done reducing. Congratulations! Here's your final answer to 5/12 + 4/7
