Key Features :
i : Great for teaching the relationship of +/- and multiply/divide; (Example 3+1=4 on one side, 4-1+3 on the reverse).ii : Familiarize children with the basic facts of multiplication and division. Quick recall of math basics, "mental math". Application and interpretation of mathematical language for important elementary concepts. Auditory/visual association.iii : Notched corners for quick organization. Large, easy to handle 6-1/4" x 3-1/4" cards. Bold, heavy type to use with large groups. Durable, thick card stock (14 pt.).iv : Self-checking (the number on the lower right of each card give the correct answer for the opposite side). Great for small groups, pairs, and whole class participation.