Carbon Dioxide + Water --> Glucose + Oxygen CO2 + H2O --> C6H12O6 + O2 Balancing the equation, it becomes: 6CO2 + 6H2O --> C6H12O6 + 6O2 Note that the reactions also require light and energy (usually written in smaller letters above or below the arrow signs). The balanced equation is the one you should write during exams, unless they ask you otherwise (which would be very odd).