Grade
1

How Many Are Hidden? Balloon Race

The number of hot air balloons in both pictures is the same.

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

The picture on the left shows 4 blue balloons and 4 red balloons. The picture on the right shows 6 blue balloons and a cloud covering an unknown number of red balloons. Blue 4 + red 4 = blue 6 + red blank.

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

In the equation blue 4 + red 4 = blue 6 + red blank, the first 4 changes to 6. How does the second 4 change if the equation is true?
  • Now both pictures have more than 8 hot air balloons each. You get to decide how many! 
    How many hot air balloons might be hidden behind each cloud? How do you know?
  • Complete the equation to make it true.
    What do you notice about how the number changed?
The picture on the left shows a cloud covering an unknown number of blue balloons and 9 red balloons. The picture on the right shows a cloud covering an unknown number of blue balloons and 7 red balloons. Blue blank + red 9 = blue blank + red 7.
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