This is a concept many of my first graders struggle with. My school uses the GO Math curriculum and I found this game very helpful to use in conjunction with more/fewer lessons in Chapter 2. It’s helpful to bring back and play again in the Chapter 10 Graphing as well.
This game helps students understand the concept of comparing groups and finding out how many MORE and how many fewer. I find that putting in it the context of kids and cookies they can better understand that there are 3 fewer cookies than kids (or 3 more kids than cookies). In my class, I made this anchor chart with the students and they played the game for multiple days. After that they were better able to answer word problems asking them to find how many more or fewer.
To play students pick a cookie card and a kid card. Draw the correct number of circles on the chart and answer the questions.