Add and subtract any fractions.
To write a fraction, type the numerator, followed by the forward slash, and then the denominator. When fractions have unlike denominators, find the Least Common Denominator and rewrite the fractions with the common denominator.

🙂 = Correct, ☹️ = Incorrect

📌 Rules

• Find a common denominator first: You can only add or subtract fractions when the bottom numbers are the same. To solve 1/3 + 1/4, find the lowest common multiple of 3 and 4, which is 12.

• Convert both fractions before calculating: Multiply top and bottom by the same number to make equivalent fractions with the new denominator. For 1/3 + 1/4, convert 1/3 to 4/12 (multiply by 4) and 1/4 to 3/12 (multiply by 3), then add the top numbers: 4/12 + 3/12 = 7/12.

💡 Tips

• Use multiplication tables to spot the match: List the multiples of both denominators until you find the smallest matching number. For 3 (3, 6, 9, 12) and 4 (4, 8, 12), the smallest shared number is 12.

• Quick typing on our platform: Typing your answer is designed to be super quick and simple! Just type your top number, a forward slash, and your bottom number like 7/12 without adding any spaces or commas.

⚠️ Warnings

• Never add or subtract the bottom numbers: Doing 1/3 + 1/4 = 2/7 is incorrect because you cannot combine fractions with different slice sizes without converting them first!

• Remember to multiply the top number too: When changing 1/3 into 12ths, you must multiply the top number by 4 as well as the bottom number. Writing 1/12 instead of 4/12 is a very common mistake.