5th Grade Controlled Experiments

Some students learn new concepts more quickly, when an experiment is involved. Experiments can make a subject more interesting and help a student retain information gained through performing the steps.. A controlled experiment relates to the differences that occur or take place between seemingly similar things. It's controlled, because the conditions, or items used in the experiment are the same or similar. This type of experiment enables 5th grade students to study the effect the experiment has by way of comparison.

Fill two same size glasses to 3/4 full with cold water. Put 1 teaspoon of sugar and one teaspoon of lemon juice in each glass and stir. Taste the water in each glass; they obviously taste the same. Add one more teaspoon of sugar and lemon juice to the second glass, but don't add anything to the first glass as this is the control glass. Taste the liquid in each and make a note of the difference. Alter the amounts of sugar and lemon juice you add to the second glass. Increase the amount of lemon and note the difference in taste, or add more sugar and make a note of the taste. Be sure to leave the first glass the same.

Fill three bottles 3/4 full of warm water. Small fizzy drinks bottles work well. Dissolve 1 tablespoon. of sugar into one bottle and 1 tablespoon of maple or corn syrup into the second bottle. Don't put any sugar or syrup into the third bottle as this is the control bottle. Put a label on each bottle to indicate what it contains; label the third bottle "control." Add 1 teaspoon of yeast to each bottle, including the control bottle. Put a small balloon over the neck of each bottle so it forms a seal. Use an elasticized band if the seal isn't tight enough. Place the three bottles in a warm place, perhaps a windowsill where there's sunlight. Check the bottles every 30 minutes. You will find the balloons begin to inflate, but at different stages. Write down the results.

Seeing how quickly different types of food develop mold is an interesting experiment for 5th graders. The environment in this experiment is controlled and remains the same throughout, but the items used are all different. Select three or four different types of food; a slice of bread, a sliced orange and a lettuce leaf work well. Put the items into three containers, then sprinkle a little water over them and leave them for about 30 minutes. Put on the container lids and then set the containers in a dark, but warm place. Check on the containers each day and get the 5th graders to write down the results they see. Each item develops different amounts of mold. Look at the mold growth under a microscope.

It's best to use two people for this experiment. Put one candle into a small glass. This is the control glass and remains the same throughout the experiment. Put another candle into a glass that's two or three times larger than the first glass. Light the two candles and place a piece of baking sheet on the top of the glasses at the same time and immediately start two timers or stop watches. See how long it takes for the candles to go out. The candle in the small glass goes out first. This is because there is not as much air in the glass and fire needs air. Once the air is exhausted, the fire goes out. Repeat the experiment using different sized glasses for the second candle, but the same glass for the first candle and compare the results.