Just to clarify…start your homework by choosing any black and white image that has a range of values like this tiger, then render it in one color to make it monochromatic. If you are using colored pencil or crayon you can make lighter or darker values by using different pressure. If you are using watercolor you can make lighter or darker values by adding more water. You can see the video below if you choose to do your homework with acrylic and need to know about tints and shades.