Many kids have a hard time retelling/summarizing a passage or story. This simple hand trick helps them tell only the most important parts of the story. One teacher I know keeps these two hand cut-outs on the wall near their guided reading table, so the kids can refer to it often. She says it’s really helpful for tons of her students.
If you wanted, you could have each student trace their own hand and label each finger at the beginning of the year. You could put them on the wall to, or glue them to the front of a folder or reading journal, etc.