Designed specifically for third grade common core, these 20 area and perimeter task cards are exactly what you need to prepare your kiddos for your state's assessment in this area.
These are excellent resources for guided math practice whole group as you view them on the smart board. They double as a great center activity, or even post them around the room for students to work in pairs to solve.
The compliment to these is theArea & Perimeter Board Game, also found here on TPT. I hope you'll go check it out as well. The area and perimeter problems are the same, but they are smaller, have answers on the back and include a game board.