fractions division

[gullpacha]

I learn division as a repeated subtraction the why in fractions division we inverse second fraction and multiply what is logic?how fraction division relate to fractions multiplications ?
thank you

 

[Dr.Peterson]

Division, in effect, asks, what number times this given number results in this other given number?

When you multiply a number by its reciprocal (e.g. 2/3 times 3/2), the result is 1.

So, for example, if I want to know what times 2/3 equals 5, I know that 5 times 3/2 will work: 5 times 3/2 times 2/3 is 5 times 1, or 5.

So to divide 5 by 2/3, we multiply 5 by 3/2.

 

[JeffM]

I learn division as a repeated subtraction the why in fractions division we inverse second fraction and multiply what is logic?how fraction division relate to fractions multiplications ?
thank you

Repeated subtractions is a definition that only makes sense with respect to whole numbers. Once you move on to more complicated numbers like fractions, you need to learn a new definition. How can you subtract something half a time?

 

[Steven G]

Please watch the video here. The beginning of the video builds up to why the rule for dividing fractions works.