I am a math intervention teacher for grades 3-5. I enjoy creating activities and worksheets that make teaching common core math standards easier. This packet aligns with the common core standard 3.NBT.2: Fluenty add and subtract within 1,000. This packet includes 12 task cards for which students will need to determine whether to add or subtract and a student response sheet. For each task card, students are asked to add or subtract either hundreds or thousands. Task cards are great for partner or group activities, station or center activities, or for students who get done early.