Activity

Grade
2

How Many Are Hidden? Packages of Presents

Both pictures have the same number of presents. There are 10 presents in each box.

How many presents are hidden behind the cloud? How do you know? How can you finish the equation to make it true?

The picture on the left show 2 blue boxes of 10 presents and 4 red boxes of 10 presents. The picture on the right shows 3 blue boxes of 10 presents and an unknown number of red boxes of presents hidden behind a cloud. Blue 20 + red 40 = blue 30 + red blank.

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

In the equation blue 20 + red 40 = blue 30 + red blank, the 20 changes to 30. How does the 40 change if the equation is true?
  • Now there are more than 60 presents. You get to decide how many!
    How many presents might be hidden behind each cloud?  How do you know?
  • Finish the equation to make it true.
    What do you notice about how the numbers changed?
The picture on the left shows 4 blue boxes of 10 presents and an unknown number of red boxes of presents hidden by a cloud. The picture on the right shows 3 blue boxes of 10 presents and an unknown number of red boxes of presents hidden by a cloud. Blue 40 + red blank = blue 30 + red blank.