Emilio was playing marbles in the first round he lost 1/2 of his marbles in the second round he lost 1/4 of his his remaining marbles in the third round he lost 1/3 of his remaining marbles he gave 1 marble to his friend he had 1 marble left how many marbles did he have when he started the game

Answer 1

If you work backwards (which is a viable problem solving strategy in grade 3 you have).
He gave a marble away and had 1 left.
So... he had 2 marbles.
But before that he had to lose 1/3 of his marbles (and still have 2 left) so... 1/3 of 3 marbles is one marble. 3 - 1 = 2 marbles : )
So working backwards again he had 3 marbles... but lost 1/4 (and ended up with three) So if he had 4 marbles and lost 1/4 that means he would loose 1 and have 3.
So working backwards with the 4 marbles we are on the final round. If he lost half his marbles and ended up with 4 marbles. So half of 8 marbles is 4 marbles... 8=4 = 4 marbles. So he must have started with 8 marbles.
You could also "guess and check" options... much later they will do the same question using algebra and the introduction of the variable x. But in grade 3, working backwards is their best option : )
Hope this helps,
Yours in Mathematical fun, Ms Pi