The Subtraction strip Board gives the child practice in figuring out and memorizing subtraction facts. The Subtraction strip board like t Additional strip board is a Board which is around 16” x 12” The Board is divided into 2×2 cm Squares across from left to right and around 11 squares from top to bottom. On the top of the Board the squares are numbered from 1-18, up to 9 the numbers are printed in Blue & from 10 to 18 they are printed in Red. A Blue  line divides the Board after # 9.  This set comes with Red & blue strips that are numbered and also has the wooden natural finish strips which are not numbered, all these are well placed in a storage box having a lid on it.