Grade
3

Mobile Math: Balance the Triangle

Look at the mobile below. What do you notice? What do you wonder?

Find the missing values so that the mobile is balanced.

A mobile with 2 strings is balanced. The left string has 1 triangle. The right string has 1 square and 2 trapezoids. The value of the triangle is 39. The value of the square is 21.

If the value of the trapezoid is now 11, how can you change the value of the square so that the mobile remains balanced?

A mobile with 2 strings is balanced. The left string has 1 triangle. The right string has 1 square and 2 trapezoids. The value of the triangle is 39. The value of the trapezoid is 11.

The total value of the mobile is up to you. What values could each of the pieces have that would allow the mobile to be balanced?

A mobile with 2 strings is balanced. The left string has 1 triangle. The right string has 1 square and 2 trapezoids. The value of each shape is up to you.
Printable Version

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Reference for Educators

Sample problems and solutions