Measuring is an abstract concept for preschoolers, but they can learn measuring if you use simple, hands-on methods. Stress the reasons why we measure things along with the how. We measure things to compare them, to track changes or so another person can understand them. For example, we follow a recipe and measure ingredients so a cake always turns out right, even if someone else is making it.
Introduce the idea of measuring as a way to compare objects long before you introduce inches or feet. For example, use your hands, a block or a piece of string to measure common items in your house. Say, "How many blocks high is your bike? How about your chair? Which one is higher? Which one is lower?" Record your findings and keep learning fun.
Weigh items on a kitchen scale or bathroom scale to compare them. Say, "Which toy is heavier -- your truck or your ball?" Make predictions before you put the items on the scale.
Introduce standardized measuring terms, such as inches, feet or pounds. Use rulers, yardsticks and measuring tapes to measure things in the house. Measure your child yearly on a wall or board and record the results to show growth. Talk about events or locations in terms of time or miles. For example, say, "In 30 minutes, we need to leave for school. That's about as long as one episode of Barney," or "It's three miles to Sarah's house. That's about as far away as the school."
Bake with your child to teach measuring. Let your child measure the ingredients, talking about cups, teaspoons and tablespoons. Set the timer and show your child how many minutes your cookies, cake or bread must bake.