When you're figuring out the area and perimeter of shapes, you might make some mistakes. Here are a few common ones to watch out for:

1. Forgetting the Formula: Each shape has its own formula, so make sure you know which one to use. Here are some examples:

   • For a square: Area = side × side
   • For a rectangle: Area = length × width
   • For a triangle: Area = 1/2 × base × height
   • For a circle: Area = π × radius × radius

2. Units: Always check the units you're using. If you measure in meters, the area will be in square meters!

3. Mixing Up Area and Perimeter: Don't confuse these two! The area is how much space is inside a shape. Perimeter is the distance around the outside.

4. Rounding Off: Be careful with π (pi) when you're working with circles. If you round it too much, it can lead to mistakes, especially when your numbers get bigger.

By keeping these tips in mind, you can avoid mistakes and get your calculations correct!