Question

How do you evaluate `1 13/15 + 4 11/15`?

Answer 1

`6 9/15`

Explanation:

Split it:

Whole numbers: `color(blue)(1+4=5)`

,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.
The fractions both have the same bottom number (denominator).
Consequently you can directly add the top numbers (numerators)

Fractions: `13/15+11/15 " "->" "(13+11)/15= 24/15`

But `24/15" is the same as " 15/15+9/15`

and `15/15=1" giving "color(blue)(13/15+11/15= 1+9/15)`
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`color(green)("Putting it all together")`

`5+1+9/15 = 6 9/15`

Answer 2

`6 3/5`

Explanation:

`1 13/15+4 11/15`

`=(15(1)+13)/15+(15(4)+11)/15`

`=(15+13)/15+(60+11)/15`

`=28/15+71/15`

`=99/15`
Dividing numerator and denominator by `3` since `3/3=1`
we get
`(99/3)/(15/3)`

`=33/5`
`6 3/5`