Photo credit: Planning Playtime
Uno Addition is a fun way for students to learn addition. I like this activity for many reasons: this is low prep, as the Uno cards randomly generate the numbers used in each equation; it is kinethetic, as students get to put the blocks together to build the amount; it is separated by color, which provides a visual separation, so that students can visually see how the parts make up the whole; and students are using numbers and blocks to see how the numbers represent actual amounts. There is a video that demonstrates this game in action too.
For more advanced arithmetic, you can still use the Uno cards, and flip 2 or 3 cards to represent double or triple digit numbers. However, the blocks would need to be eliminated, as they would get unwieldy with double and triple digit numbers.