Where did 60 x 2 and 60 x 4 come from? Elaborate…

Draw a model to start then both at 6 units per person.

If Ben sold 2/3 of his stickers, after the model cutting, you will realise that Ben sold 4 units of stickers.

If Cai sold 5/6 of his stickers, after the model cutting, you will realise that Cai sold 5 units of stickers.

In total, they sold 9 units of stickers.
They have 3 units of stickers unsold.

3 units —> 180 stickers
1 unit —> 60 stickers
6 units —> 360 stickers

So Ben was given 360 stickers.

1/3+1/6=3/6… so therefore 3unit =180 unsold tickets, So 1 unit is 60ticket Ben has 60*2=120unsold tickets, 60 *4=240 sold tickets, so the total of tickets Ben has is 360 tickets, ??!???

Careful here.

1/3 of Ben’s stickers + 1/6 of Cai’s stickers cannot be added together just like that.

These are fractions of different people’s stickers.

We can only add fractions belonging to the same base quantity, ie

1/6 of my stickers + 2/6 of my stickers = 3/6 of my stickers.

So in other words, for example,

3/5 of red marbles + 1/10 of green marbles

does not equal to 7/10 of all marbles.