Check your printer settings like this:

The Mac version:
PC version here.

You may not be aware, but your printer could default to color every time you print. That means that it costs 17.5 cents per page instead of 2 cents per page. Do this quick check when you print to make sure you aren't accidentally using the most expensive setting.

You will need to do this for each item printed. The ricoh will automatically print in black and white if used as a printer.

Notice below that my default printer is the library color printer. Yours will likely be your classroom printer.

Notice that Color is the default preset.

by clicking the arrow, I can change that to Black and white.

When finished, click print.