One of the interesting ways you can get your elementary students to work with mental math is to use visual patterns. For example, if you take all the face cards out of a set of playing cards, you’ll have the number cards remaining. Take a couple of these decks and cover up the numbers and the small designation of the suit. What you’ll have left is just the number pattern on the card. You can then use these cards as flash cards to get students to use their mental math muscles.