This is a set of 17 charts and 4 boxes of number tiles. The tiles have the numbers printed in red, green, yellow and blue to denote addition, subtraction, multiplication and division. All the charts have blocks of squares printed on them. Each control chart has the basic combinations and the results printed on them. Each work chart has the basic combinations without the answers printed on them.Differences with premium: Differences are in the boxes used. In premium range we use polished wooden boxes, whereas for economy range we use boxes made of pre-laminated wooden sheets. Also, the cards are painted on the sides in the premium range whereas in the economy range, we do not paint the sides.