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 : Sold as 2 packs, each pack contains 90 classroom-size flash cardsiii : Cards measure 6.25" x 3.25"iv : To familiarize children with the basic facts of addition and subtraction. Quick recall of math basics, "mental math". Application and interpretation of mathematical language for important elementary concepts. Auditory/visual association.