As an introduction to balancing equations, this should be given to students after they know what a chemical equation, coefficient, and subscript are.
Students will need colored pencils to complete this activity (colors are suggested, but as long as they commit to the colors they choose for each element, this will work). They need to start by coloring in one of each molecule in the equation. They next need to see which side of the equation needs more of an element, and color in an entire molecule which contains said element. They need to continue this process until there are equal numbers of the atoms colored in on the reactant and product side of the equation.
The students finally need to count the total number of each type of molecule they colored in, and put that number (the coefficient) on the line in front of the symbol in the equation. All numbers but "1" are written. There are more than enough molecules drawn, so students need to go through this carefully (and not randomly color).