fractions: can't remember when to flip which fraction or why

[†raychill†]

okay well i was doing good in algebra and took a test and failed... flat out failed... no reason given just the letter D on my paper... after reviewing each problem i realizied it was fractions... sorta... but i just cant remember for the life of me when to flip which fraction and why. like the problem ¾ divided by ¼ which one do I flip and when do I multiply instead?? am i the only one who doesnt get this?

[stapel_eliz]

The short version is "because dividing by a number is the same as multiplying by its reciprocal". For instance, you can divide by 2 = 2/1, or you can multiply by 1/2.

Since it is the divisor that gets flipped, you would then flip the second (or "bottom") fraction, and then multiply.

[†raychill†]

okay i get it now...thanks