Students can play a slope intercept game at http://www.math-play.com/slope-intercept-game.html
and can due a review of slope at Khan Academy and work on this subject watching a video and doing follow-up problems at
https://www.khanacademy.org/math/cc-eighth-grade-math/cc-8th-linear-equations-functions/8th-slope/v/graphical-slope-of-a-line
Good fortune to you!