Keeping track of your child's growth can be a fun activity! I hammered nails in a 7' High 5-6" Wide board and hung it on a 2x4 on our playroom wall. Using a marker I lined the board and put marked each line by inches and feet. Every 6 months or so I wrote each child's name next to the height each measured along the name and date of the measurement. Now our grandchildren LOVE to see how tall they are in comparison to their parent! It makes for a fun number activity.