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# Which is heavier?

Alignments to Content Standards: K.MD.A.1 K.MD.A.2

Students will need various items to compare weights, a balance scale, and a recording sheet with four sections with enough space for a small drawing. The students work in pairs. They choose two items to compare weights. Using the balance scale, they put one item on each side of the balance scale. Then they draw the two items and circle the one that is heavier. They continue same steps with different pairs of items.

## IM Commentary

The purpose of this task is for students to use a balance scale to compare the weights of two different objects. It is best if the objects appear to be close to the same weight so that comparing them on a balance scale is meaningful. This task also introduces students to the way in which a balance scale works, which is not obvious.

## Attached Resources

• Blackline Master
• Blackline Master 2A
• Blackline Master 2B
• ## Solution

The students should become familiar with the word “heavy” and its reference to weight.

#### redbaron says:

over 4 years

This task seems to resemble 1.MD.2 more than K.MD.1, where students are asked to describe measurable attributes. Measuring processes (at least ones that involve numbers) do not seem to occur until 1st grade. This said, I do think K.MD.1 is the best standard for this task, since I don't see much potential anywhere else for students to explore the concept of weight. However, should it be clarified in the commentary that the nature of this task fits K.MD.1 strictly as an exploratory activity, rather than an assessment one?

#### Kristin says:

over 4 years

Thanks, redbaron, I completely agree with you that as originally written, it went well beyond the standard, so I modified it to meet this standard and then created a related task for third grade when students are working with mass. Check that one out and let me know what you think of the two variants:

https://www.illustrativemathematics.org/illustrations/1929

#### redbaron says:

over 4 years

Sure Kristin,

I do think this now fits soundly with K.MD.2, and that discussions about "heavy" tie it to K.MD.1 as well. The third grade standard, which did not even occur to me, seems particularly relevant to this kind of task as well. I do have some questions about the 3.MD.2 version though, which I'll go ahead and log on that page.

#### megan says:

almost 6 years

Hi, I don't see a blackline master?

#### Cam says:

almost 6 years

Hi megan,

We've now got website functionality to make resources publicly available. The resource is located at the bottom of the task, right above the solution.

#### Kristin says:

almost 6 years

It should be up within the next month--there is a change to the website we need to make in order for it to appear on the public side.