In RPG gaming of any type, characters will often aquire gathering quests. Gathering quests require you to search the world for X amount of items of a particular type.
Throughout the quest it’s typical to use the structure X/X. Where the first X stands for how many items you have collected and the second X stands for how many items you need in all.
When I play with my 5 year old son I pause after we gather an item and ask him 3 questions.
1. How many total items do we need?
2. How many items do we have?
3. How many items do we have left to get?
I have found this to be a great way to reinforce simple addition and subtraction while enjoying games together. As time goes on I will use the same quests to teach him about fractions.