Grams and Kilograms
Background Information & Activities

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Help children develop measurement skills and understand and explore different units of mass, weight, length, and volume. This movie will explore grams and kilograms. It will also explain how to use a balance scale and compare masses. We recommend doing plenty of hands-on activities and encouraging children to explore and measure the objects around them.

Remind children that everything around us is made of matter. Our computer, keyboard, mouse, table, chair, and the clothes on our backs are made of matter. Even the air we breathe is made of matter. Mass is the amount of matter in something. We can use metric units like grams and kilograms to measure mass.

Explain that a gram is the base unit of mass. A paper clip, a pen cap, and a peanut each have a mass of about one gram. What other objects have a mass of one gram? If possible, use a scale to measure masses of small objects. Remind children that the abbreviation for grams is "g." Measure and compare different masses of objects and use key terms such as "greater than" or "less than" as you compare. You may want to have children record masses in a chart or graph.

If possible, have children use a balance scale to measure or compare mass. Explain that a balance scale has a tilting beam with a container or pan on each end. To calculate the mass of an object, you can place it on one end of the beam and place known weights or masses on the other until the beam is balanced. Most scales have a guide that tells when the scale is balanced. You can also use the balance scale to compare the weights or masses of objects. Together with children, use a balance to compare masses. Which has a greater mass, an apple or an orange? A pencil or a pen? A marble or an eraser? Have children make predictions and use the scale to test their predictions.

Remind children that a kilogram is equal to 1,000 grams. A baseball bat, a dictionary, a pineapple, and a bag of flour are each about one kilogram. Remind children that the abbreviation for kilograms is "kg." Calculate the masses of large objects in kilograms and if possible, use a scale to compare larger masses. Have children predict the masses of large objects such as a dictionary, a watermelon, or a pair of boots.

It is important for children to choose appropriate units when they measure mass. Explain that grams are a good unit to use when they measure thing with smaller masses. For example, a carrot, a zucchini, and an onion are pretty lightweight and most likely have masses less than a kilogram. So, it makes more sense to measure in grams. In contrast, a pumpkin can be fairly heavy and have a mass greater than a kilogram. Thus, using kilograms is a better option.

Provide opportunities for children to measure objects in grams or kilograms. Help them get familiar with units of mass. Challenge children to make a prediction about an object's mass using the appropriate measurement unit and test their predictions with a scale.

See more lesson plans and resources: BrainPOP Educators.

Grams and Kilograms Teacher Activities

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Comparing Masses

Screen the Comparing Numbers movie and then have small groups of students use a scale to measure and compare the mass of different objects. They can write number sentences to compare the measurements by using the greater than, less than, or equal symbols. If students are using a balance scale, they may want to draw pictures of their scales to go along with their number sentences. Be sure to remind children that on a balance scale, the beam tilts toward the object with the greater mass.

As Big As A Whale

Have students pair up to research the mass of different animals. Encourage them to choose different types of animals, both large and small. Then have them find equivalent masses to help put the measurements in perspective. For example, a lion has a mass of about 200 kilograms. That's the same as about eight third-graders! Have students work together to come up with facts and share them with the whole class.

Grams and Kilograms Family Activities

© 1999-2013 BrainPOP. All rights reserved.

Mass of a Meal

If possible, challenge your child to measure the mass of everything he or she eats in a day. You may need to show your child how to tare (or zero) the scale so that he or she doesn't measure the plate's mass along with the food. Have your child record what she or he eats and the mass of each item. Then use a calculator to find the total mass of a day's worth of food.

I Spy

Play a game of "I Spy" with your child, but focus on masses. For example, you might say "I spy with my eye an object that has a mass of two grams" or "I spy with my eye an object that is greater than a kilogram." Then have your child predict which object you’ve chosen using estimation and check the prediction with a scale. Have your child write down the objects and their measurements. Then, switch roles!