Show students the yardstick. Ask them what they think it measures.
Tell students that a yardstick is one yard long. One yard is the same as 36 inches, or three feet.
Take three rulers and put them together. Explain that each ruler is 12 inches long, so three rulers together are 36 inches, or one yard, long.
Ask students what types of things they might measure with a yardstick. Give them a few examples and have them share whether they would measure with a ruler or a yardstick (smaller things would be measured with a ruler, larger things with a meter stick).