Line a large baking sheet with wax paper and set aside.
Open the Rice Krispie Treats and discard the wrappers.
Cut the Rice Krispie Treats in half.
Pour the yellow candy melts into a long, shallow microwave safe dish. Heat for 30 seconds and stir. Repeat until the candy melts have fully melted. If the mixture seems thick, add 1-2 tsp of coconut oil and stir. This will make it easier to dip the Rice Krispie Treats.
Place one Rice Krispie Treat into the chocolate at a time and gently coat using a spoon or spatula. Use a fork to lift out and allow the excess chocolate to drip back into the bowl.
Place the candy coated treat on the wax paper lined baking sheet.
Repeat this process until all the treats are covered in chocolate.
Place the baking sheet in the fridge for 15-20 minutes to allow the chocolate to harden.
Once the chocolate has set, use the Wilton black gel icing to make the small ruler marks and numbers. Repeat with all the treats.