We can learn about the world around us by taking measurements. Different tools help us make different kinds of measurements. Here are a few tools for measuring.
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A thermometer measures temperature. It tells us how hot or cold something is.
A scale measures weight. It tells us how much something weighs. Which of these two loads is heavier?
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A ruler measures length. It tells us how long or short something is. How many inches long is this eraser?
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This is a sundial. It is one of the oldest tools for telling time. A sundial has markings. They stand for the hours of daylight. It also has a pointer. The pointer casts a shadow. The shadow moves as the sun moves. This is one way people could tell time long ago.