Lil’ Sister

standards: K.MD.2,  K.CC.6

Act 1

Look at the picture

Lil' Sister

  1. What questions come to your mind?
  2. How much shorter is Lil’ Sister than her Big Sister?


Act 2

What information do you need to solve the problem?

Lil' E

Big Sister

Lil' Sister

Lil’ Sister


Act 3

How much shorter was Lil’ Sister than Big Sister?  Compare your answers and share your solution strategy.


Act 4 (the Sequel)

1. Change the unit!  Can you compare the sisters’ heights using a different unit of measure? (ie: pattern blocks, paper clips, pencils, etc…) 

Teacher Note: watch for iteration and students using the same pattern block.


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6 thoughts on “Lil’ Sister

  1. I just completed this task in a kindergarten classroom. It’s a wonderful task! It hits on more than just measurement standards. The students were engaged as they struggled through making sense of the information given. Many students just wanted to compare the cubes to the picture, instead of determining the amount of cubes used in the actual picture. Once they got over that hurdle, students applied their counting skills to determine the number of cubes long the big sister and little sister were. Many students were able to replicate it with their own snap cubes. In the end, as a class, we discussed the difference in height of the sisters and compared our findings to the reveal provided.

    • That’s awesome Jenise and thanks for sharing! A lot of times I find that these tasks take on a life of their own and go much further than was originally intended. Crazy how Common Core expects students to have cardinality through 20 and here you have them comparing numbers within 120. Sounds like 1st grade stuff to me!

      Well done!

  2. BTW, was brought here by a link in the Georgia Standards of Excellence curriculum. What a great resource!

    One immediate extension question is how tall the sisters are in standard units. Before looking at this, I would have guessed that the unifix cubes are 1 inch. However, I doubt the older sister (7 years old) is already 5.5 feet tall!

    Second gut reaction is that the cubes must be 1 cm, because surely they picked a standard unit, right? However, that is very unlikely as well. Thus, the open question for students: how tall (in standard units) do we think the sisters are? What do we think is the height of each cube?

    This can lead to measuring cubes (if your class has similar ones), looking for that information online, or, even better, looking at height data like in this tool.

    • The Georgia Frameworks are a treasure trove of goodness. Glad you found them Joshua.
      What’s funny is the cubes come in different sizes depending on the company you buy them from. Some are an inch, while others are 3/4 inches long.
      With this task being geared towards the primary grades I wanted to keep non-standard units of measurement but you’re the precision of giving standard units (cm, inches, etc..) would lend itself to a natural extension. I added your suggestion as a sequel to the task. Cheers.

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