Here in France as part of a numeracy drive the children in my daughter's class were asked to bring in their collections of one hundred things.
We took a cheap canvas, bought in Lidl, and painted it in green, blue, and turquoise acrylic paint, then when it was dry we painted on a tree trunk and branches.
Isabelle counted out one hundred coins, fifty two centimes and fifty one centimes. Then she split them into piles of twenty-five and put two of the piles into two bowls filled with Vanish OxyAction to shine them up. It didn't work as well as we would have liked, cheap cola would probably have had been a better choice, but we didn't have any so we made do!
When the coins were dried Isabelle stuck them to the tree, and then she painted on some flowers to bring it to life a bit. Here is the final picture, and she is quite rightly proud of it!