Question #fea46

2 Answers
Sep 1, 2016

#8 div 2# is the same as #8/2 = 4#

A fraction is a quicker and easier way of writing a division, especially in the algebra which lies ahead.

Explanation:

Writing a division as a fraction is a more useful way of showing the division. They mean exactly the same thing!

#2 div 3 =2/3 " "20 div 4 = 20/4 = 5#

#5 div 10 = 1/2# It can also be shown as #5/10 = 1/2#

As you work more and more with Algebra you will find that you use the #div# sign less and less, and divisions are shown as fractions.

Sep 5, 2016

Something to think about!

Explanation:

#color(brown)("The big question is: does it actually mean divide?")#

#color(green)("I can only leave you with an open question")#

A fraction is something that has been so much a part of my life for so long that I have not really given much thought to this question.

Consider what a fraction is:

#("count")/("size indicator of what you are counting") ->("numerator")/("denominator")#

The size indicator is how many of what you are counting it takes to make a whole.

The line's prime function is to separate the two numbers. Its very existence and agreed format also tells us that we to consider the relationship between the two numbers in a particular way. That we are counting parts of a whole and declaring the size of what we are counting.

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The problem comes from the tendency and convention to disregard something. Let me explain:

It is all to do with ratio and I wish to demonstrate this using a right triangle
.Tony B

If you are familiar with a little trig consider the value (ratio) of #tan(theta)# full name of Tangent.

#tan(theta) = ("Length of AC = 4")/("Length of BC=3") = 4/3#

Suppose we were to change the 3 into 1 we have:

#tan(theta)=(4-:3)/(3-:3) = (1.33bar3)/1#

People do not bother to write the 1 so you end up with just #tan(theta)=1.33bar3#

This is actually saying we have #1.33bar3# of AC for 1 of BC

However there is a tendency for people to say divide the 3 into 4 and you get #1.33bar3# which is true but is it what #tan(theta)# is actually declaring. #tan(theta)# is saying that for 1 along you get #1.33bar3# up.

Looking at a fraction, say #1/2#. Divide 2 into 1 and you get 0.5. However, like in the ratio, what is missed out is that it really is #0.5/1# because we have #(1-:2)/(2-:2) = 0.5/1#

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#color(green)("The open question!")#

#color(green)("The problem is that numerically they behave in the same way. So does it mean divide or not?")#