This week is easy! I realize shopping carts are impossible on which to leave coins... so consider leaving a piece of paper or cardboard on which to put the coin.
Perhaps a child will find that quarter and spend it on one of those little candy machines. You might just make their day... especially if you leave a kindness note along with it in an envelope entitled "To the random kid who finds this...," include a drawing from your child, or something else to that effect.
Get creative; have fun; ask the next kiddo to pay it forward.
XO,
Lindsay