What is the name of this poem? What is this poem?

There is this poem that is from a childs point of view about money, the kid is given a $5 and then someone offers the kid 2 $1s in exchange for the 1 $5, and the kid accepts because didnt you know 2 is more than 1 and she keeps exchanging for more objects of less value until her original $5 is reduced to a few pennys.