Plants make their own food by photosynthesis. Carbon dioxide from the air and water from the soil are changed into glucose and oxygen. The word equation is: carbon dioxide + water → glucose + oxygen. Light is needed for the reaction, so it is written above the arrow.
You must recognise the chemical symbols: CO2 for carbon dioxide, H2O for water, C6H12O6 for glucose and O2 for oxygen.
Photosynthesis is an endothermic reaction. This means energy is taken in from the surroundings. In photosynthesis the energy is transferred from the environment to the chloroplasts by light. Chloroplasts are the parts of a plant cell where the reaction happens.