When you use algebra tiles, is represented with algebra tiles as a shaded small square and is always a positive unit. The opposite of , written , is an open small square and is always negative. Let's explore the variable ‑ . The variable ‑ is shaded, but is the number represented by a variable such as always positive? Why or why not? The opposite of the variable , written , looks like it might be negative, but since the value of a variable can be any number (the opposite of is ), what can you say about the opposite of the variable ? Is it possible to determine which is greater, or ? Explain. What is true about ? What is true about (the sum of a variable and its opposite)?