A fraction of the remainder

Aiden had some stickers. He gave one third of them to his brother. He then gave two fifths of the remainder to his sister. He had 36 stickers left. How many stickers did he have at first? Try it first. Pause if you like. The two fifths is of the remainder, not of all his stickers. So the two fractions cannot just be added. Draw all of Aiden's stickers as one blue bar. This whole bar is everything he had at first. One third means one part out of three, so cut the bar into 3 equal parts. One part is his brother's, and it is given away. The other 2 parts are the remainder. Two fifths means 2 parts out of 5 equal parts. So cut every part of the bar into 5, right across. The cut runs through the whole bar, so every unit stays the same size. Count the units in the remainder. 2 parts of 5 units each, so 2 times 5 is 10 units. Now cut the remainder into 5 equal parts. 10 divided by 5 is 2, so each part is 2 units. His sister gets 2 of those parts. 2 times 2 is 4 units. The rest of the remainder is left. 10 minus 4 is 6 units. Aiden had 36 stickers left. So 6 units is 36. 1 unit is 36 divided by 6, which is 6. The whole bar is 15 units. 15 times 6 is 90. So Aiden had 90 stickers at first. The one third is of the whole bar, but the two fifths is of the remainder.