Write & Identify a Real World Algebraic Expression | 6.EE.B.6

The video tutorial guides students through identifying an algebraic expression to represent a real-world situation involving a box and marbles. The box has a mass of 50 grams, and each marble adds 3 grams. The variable N represents the number of marbles. The tutorial explains how to construct the expression 50 + 3N to find the total mass. Students are encouraged to pause and solve the problem before the solution is revealed. The video concludes with a review of the correct expression and an invitation to continue learning math.

What does the variable N represent in the context of this problem?

Explain how you would derive the algebraic expression for the total mass of the box and the marbles.