How do you make the print darker on a Canon P120-DH calculator?

To make the print darker on a Canon P120-DH calculator, you typically need to adjust the print density settings. Locate the "Print Density" or similar option in the calculator's menu, and increase the density to a higher setting. If the calculator does not have this option, check the ink ribbon or cartridge to ensure it is properly installed and has sufficient ink. Lastly, cleaning the print head may also improve print quality.