# Question Video: Using Scales to Compare the Masses of Three Objects Measured in Kilograms Mathematics • 3rd Grade

Isabella weighed these boxes of fruit. Finish these sentences to describe the masses of the boxes. The mass of the box of strawberries is ＿ kg. The box of ＿ is the heaviest. The box of bananas is ＿ kg lighter than the box of oranges.

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### Video Transcript

Isabella weighed these boxes of fruit. Finish these sentences to describe the masses of the boxes. The mass of the box of strawberries is what kilograms. The box of what is the heaviest. And the box of bananas is what kilograms lighter than the box of oranges.

This question is all about comparing the mass of some boxes of fruit. And we don’t need to do any weighing to do this because Isabella has done it for us. We can see that she’s weighed a box of bananas, a box of strawberries, and a box of oranges. And each of her sets of scales are balanced. So this means we just need to count how many kilograms she’s put on the other end. And then we’ll know how heavy each box is.

How heavy is the box of bananas? This large weight on the end here is labeled five kg. We know this stands for five kilograms. Then we have one labeled two kilograms and two more that are labeled one kilogram. Five and two make seven. And then if we add the other two ones, we have a total of nine. The box of bananas weighs nine kilograms altogether. Now, let’s look at the box of strawberries. If we look at the weights that are labeled again, we can see one that’s labeled with a two on it. And there’s a two kilograms on the top, another two kilograms here, and a one-kilogram weight on the end.

If we count in twos three times, we get a total of six. Two, four, six. And then if we add the one kilogram, this is seven kilograms altogether. Finally, if we look at the box of oranges, we have a five-kilogram weight and another five-kilogram weight and, on the top, we have a one-kilogram weight. Five and five make 10, and if we add one more, that’s 11. The box of oranges weighs 11 kilograms.

Did you notice that each of these masses is in kilograms? And because we’ve weighed these objects in the same unit of measurement, all we have to do to compare them is to look at the numbers. Let’s go through the sentences now and see if we can complete them. The mass of the box of strawberries is what kilograms. We’ve already worked that out, haven’t we? Three lots of two and then one more is seven kilograms. The box of what is the heaviest. As we’ve just said, because everything is measured in kilograms, we just need to compare the numbers. Which is the largest number out of nine, seven, or 11? It’s 11, isn’t it? So 11 kilograms weighs most, and we can say the box of oranges is the heaviest.

Finally, the box of bananas is what kilograms lighter than the box of oranges. Well, we know that the box of bananas weighs nine kilograms. And the box of oranges weighs 11 kilograms. What’s the difference between these two masses? Nine, 10, 11. That’s a jump of only two kilograms, isn’t it? So we can say that the box of bananas is two kilograms lighter than the box of oranges. We’ve used the pictures of the weighing scales to compare the masses of these three boxes of fruit. And we found that the mass of the box of strawberries is seven kilograms. The box of oranges is the heaviest. And the box of bananas is two kilograms lighter than the box of oranges.