This is an activity that my students have done during math intervention; students have 5 counters with a yellow side and a red side in a bowl that they shake and spill. Students divide the counters into a red pile and a yellow pile to count each amount. After students complete the activity, you can talk to students about addends and the sum for each set of red and yellow combinations. Then students can do the back and write the corresponding equation.
After students have done this with 5 counters, you can do this activity with 6 counters or 10 counters as well.