Robert is preparing a poster-board presentation. He wants to make a decorative pattern with 10 squares to fill part of the poster. The area of the poster board is 720 square inches. To find how much space Robert will have left for his presentation if he uses squares with 7-inch sides, evaluate 720 − 10s2 when s = 7 .
If s = 7, then 10s^2 = 10(7^2) = 10(49) = 490
Therefore, 720 - 10s^2 = 720 - 490 = 230 square inches. Answer: \boxed{230}.