Estimation is often a tricky concept for kids to grasp. Estimating what the total will be at the grocery store is a great authentic way to reinforce this concept. Kids can start with estimating at $2.00 per item. (This is also great practice for younger children to count by twos.) This can be refined to adding more dollars for more expensive items and eventually rounding up or down to the nearest dollar.
*My grandmother taught me to do this using $0.50 per item…I guess we can teach inflation using this activity also!