Children will have fun learning simple arithmetic with these LARGE 8.5" x 11" monkey calculators. Choose the Monkey ADDER (sold separately) for help with addition, the MONKEY SUBTRACTOR for help with subtraction, or the MONKEY MULTIPLIER (sold separately) for help with multiplying. Then slide the monkey's feet so his toes point to the numbers you want to add, subtract, or multiply and the correct answer will appear in the ring between the monkey's hands.