This is now a 14-page PDF that contains matching cards, warm-ups, and worksheets. The matching cards include square numbers shown in 4 different forms (exponent form, standard form, expanded form, and as an array). I have updated this file to include the cards in 2 different sizes, based on a good suggestion from a purchaser. The warm ups are in half page format and include practice with mainly square numbers, but a few cubed numbers. The worksheets then add in other exponents and writing numbers in expanded form using exponents to represent powers of ten.
I have used all of these materials with my above-level fifth graders, and have found that the kids needed more exposures than I would have guessed to the actual array/expanded form/standard forms. That's why I created the matching cards so that we could continually revisit what an exponent represents. (Otherwise, I have kids who think that 3 squared is 6.)
This file contains 3 full-page worksheets, 3 pages of small matching cards, 6 pages of the same cards in a larger format, and 2 sheets with half-page warm-ups.