In order to round to the nearest 100 you look at the 10s place.
It's 7 which means we round up. So 178 rounded to the nearest 100 is 200.<span />
Well 58.19 divided by 2.74 will equal 21 and random number after decimal so it will be 21 days
So in 5 weeks, Marcie will have collected 25 stickers, and given away 15. She will have 10 stickers left. I hope that this helps! :)