Before we talk about photosynthesis in general biology, I throw the photosynthesis equation at the students and make them interpret it (in a guided manner). Attached is the instruction sheet that I give the students to help walk them through understanding the parts of the equation and starting to think about the parts of the plant that utilize each input. Students make a big poster with groups (my students are grouped in 4's) following the instructions on the sheet.
My students come in with basically no chemistry background, so I also use this as an intro to seeing how equations are balanced (they don't balance it themselves, but quickly realize that the amount of matter on each side is equal), understanding inputs/outputs (NGSS terminology that fits nicely with future modeling activities you may use), identifying atoms and molecules, and just learning how to interpret "scary" information that's not so scary after all!
This activity goes so well in my classes--I would never go into explaining photosynthesis without it!