Free Printable Main Idea Worksheets (Grades 3-4)

A sourdough starter is a jar of flour and water with wild yeast living in it. The yeast is alive, so it has to be fed.

Feeding is simple. Pour out about half of what is in the jar. Add a few spoonfuls of flour and the same amount of water. Stir it until it looks like thick pancake batter.

Do this once a day if the jar sits on the counter. If you keep the jar in the refrigerator, the yeast slows down, and once a week is enough.

You will know the starter is healthy when it doubles in size a few hours after a feeding and smells a little sour, like yogurt. If it smells sharp, like nail polish, it is hungry. Feed it twice that day.

A starter that is fed can live for years. Some bakers have kept the same jar going since before they were born.

1An octopus has no bones. It can pour its whole body through any hole big enough for its beak. The beak is about the size of its eye. Aquarium keepers learned this the hard way.

2In 2016 an octopus named Inky pushed the lid off his tank. He crossed the floor of a New Zealand aquarium. Then he went down a drainpipe that led to the sea. Staff found a wet trail and an empty tank.

3Escapes are not the only sign. In labs, octopuses open jars to reach a crab inside. They remember which keeper fed them and which one poked them. They still know weeks later. Some carry two halves of a coconut shell across the seabed. They climb inside when a hunter swims past.

4This is strange. An octopus is a mollusk. Its closest relatives are clams and snails. Whatever an octopus is doing, it worked it out on a branch of the family tree far from ours.

A honeybee finds a patch of flowers half a mile from the hive. She cannot draw a map. She cannot speak. Yet within minutes, dozens of other bees fly straight to those flowers.

She tells them by dancing. Back at the hive, the bee runs in a figure eight and waggles her body down the middle of it. The direction she waggles points the way to the flowers. The longer she waggles, the farther away they are.

The other bees crowd around her in the dark. They cannot see the dance. They feel it, and they listen to the buzz she makes as she shakes.

Scientists have watched this dance for almost a hundred years. It is one of the few times an animal tells another animal about a place that is nowhere in sight.

Behind our school there was a strip of dirt. Nothing grew there but weeds. People walked past it every day.

In March, Ms. Ruiz asked her class a question. What could we do with that corner? The class made a list. Then they picked one idea: a garden.

They pulled the weeds. They dug in old leaves to feed the soil. They planted beans, carrots, and sunflowers.

By June the sunflowers were taller than the second graders. The kitchen used the beans in lunch. Kids who never liked carrots ate carrots they had pulled up themselves.

The strip of dirt is still there. It just does something now.