Grade
2

How Many Are Hidden? Boxes of Markers

The number of markers in both pictures is the same.

How many markers are hidden behind the cloud? How do you know?

How can you finish the equation to make it true?

Blue 40 + Red 12 = Blue 20 plus red blank. The picture on the left has 4 boxes of 10 blue markers, 1 box of 10 red markers, and 2 single red markers. The picture on the right has 2 boxes of 10 blue markers, and a cloud with a red question mark for the number of red markers.

What do you notice about how the blue number changed? What about the red number?

In the equation blue 40 + red 112 = blue 20 + red blank, the 40 changed to 20. How would the 12 change when the equation is true?
  • Now there are more than 52 markers. You get to decide how many! How many could be hidden behind each cloud? How do you know?
  • Complete the equation to make it true. What do you notice about how the numbers changed?
Blue 50 + Red blank = Blue 45 plus red blank. The picture on the left has 5 boxes of 10 blue markers and a cloud with a question mark for the number of red markers. The picture on the right has 4 boxes of 10 blue markers plus 5 single blue markers, and a cloud with a question mark for the number of red markers.
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