### Home > MC2 > Chapter 2 > Lesson 2.1.3 > Problem 2-41

2-41.

Solve the number puzzles below.

If I add

to my number, I get . What is my number?

Based on the number line, what was the original number?If I start at

on a number line and end up at , what direction did I move? How many units did I move? Experiment with the number line and use your observations to answer the question.

If I moved to the right

and moved to the left , what can you tell me about my ending position? Draw a sketch with a number line similar to part (a) and (b).

After drawing arrows

to the right and then to the left, what do you notice? It is the same as the starting position.

Can you see why?