Subtraction Strip Board
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 nat.
Activity:
"While using the strip board 1 the child practices the equations of the subtraction tables 1-18. 2. To learn the mechanism of subtraction. 3. To know subtraction combinations. 4. Memorization of subtraction facts."