Question: Here are the first three steps in a pattern. How many tiles will there be when $s = 10$? tiles Explain your thinking. $s = 1$ $s = 2$ $s = 3$ Graph shapes and math: In the center-left graph area, there are three purple tiled rectangles showing a pattern; for $s = 1$ there is a 1-by-2 rectangle with 2 tiles, for $s = 2$ there is a 2-by-3 rectangle with 6 tiles, and for $s = 3$ there is a 3-by-4 rectangle with 12 tiles. The shape appears to increase by one row and one column each step, so the pattern is $s \times (s + 1)$.

1. **State the problem:** We want to find how many tiles there will be when $s = 10$ in the pattern where the number of tiles forms a rectangle of size $s$ by $(s+1)$. 2. **Identify the formula:** From the pattern, the number of tiles at step $s$ is given by the formula: $$\text{tiles} = s \times (s + 1)$$ This means the number of tiles is the product of $s$ and $s+1$. 3. **Apply the formula for $s=10$:** $$\text{tiles} = 10 \times (10 + 1)$$ $$= 10 \times 11$$ 4. **Calculate the product:** $$= 110$$ 5. **Interpretation:** When $s = 10$, there will be $110$ tiles in the rectangle. **Final answer:** There are $110$ tiles when $s = 10$.