# Math Help - adding 2 fractions

hi, im having a mental blank and can't think what 1/3 + 1/5=, so could someone help me remember?

2. Originally Posted by andyboy179
hi, im having a mental blank and can't think what 1/3 + 1/5=, so could someone help me remember?
What's the common denominator?

3. Just to clear up the denominator is the LCM. Lowest common multiple. So basically which number will both of the denominators fit in?

4. very sorry i was meant to put, 1/3 x 1/5!
sorry!!

5. Originally Posted by andyboy179
very sorry i was meant to put, 1/3 x 1/5!
sorry!!
In that case, you just multiply numerators with numerators, and denominators with denominators..