For this activity, I taught my little kiddos the song "Five Little Ice Cream Cones" first, then I introduced the play mat. When we were done playing together in the whole group setting, I put this activity out in a center for them to practice their subtracting skill.
The song goes like this: "Five little ice cream cones standing in the row. Each has a scoop in an ice cream cone. Out came the sun and it's shown all day. One little ice cream cone melted away. How many are left?...."
When they play on the play mat, they can pick out a number card to tell them how many ice cream cones is melting away?