1/12 + 5/6?

just really don't understand. bolded text

2 Answers
Mar 27, 2018

#11/12#

Explanation:

You cant directly add these two, you need them to be of the same denominator if you want to add them

Now, to give the fraction #5/6# a denominator of #12#, we can multiply the numerator and denominator by #2#.

Now the fraction is #10/12#

Now you can add them #(1/12)+(10/12)#

=#11/12#

Mar 27, 2018

#11/12#

Explanation:

#color(blue)("The teaching bit")#

A fraction structure is such that we have:

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

You can not #color(purple)("DIRECTLY")# add or subtract the 'counts' (numerators") unless the 'size indicators' are the same.

You have been doing this for years without realising it.

Did you know that you can write whole numbers like this:

#1,2,3,4,5" and so on as: "1/1,2/1,3/1,4/1,5/1...#

So for example #2+3# is really #2/1+3/1= 5/1#

THEIR SIZE INDICATORS ARE THE SAME!
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#color(blue)("Answering the question")#

Multiply by 1 and you do not change the value. However, 1 comes in many forms. So you can change the way something looks with out changing its value.

#color(green)(1/12+[5/6color(red)(xx1)] color(white)("dddd") ->color(white)("dddd")1/12+[5/6color(red)(xx2/2)] )#

#color(green)(color(white)("dddddddddddddddd")->color(white)("dddd")1/12+10/12)#

Now we can DIRECTLY add the counts. At this stage adding counts (numerators) does NOT change the size indicators (denominators).

#color(green)(color(white)("dddddddddddddddd")->color(white)("dddd")11/12)#