Wooden board 12 squares by 18 squares with the numerals 1-18 printed across the top. A wooden box contains 9 red wooden strips and 9 blue wooden strips both printed with the numerals 1 to 9 and 18 natural wooden strips of varying lengths. Children use the Subtraction Strip Board by selecting subtractioncombinations of one through eighteen, thus reinforcing the child's comprehension of subtraction tables.