I have a mixed age class this year (blended, looped, whatever). I have my first graders (who I had as kindergarteners last year) and a new batch of kindergarteners. There is quite a difference in ability (from not knowing letters to knowing how to read). The first graders have done a good job so far of encouraging the "youngers" (we call them olders and youngers). Today a first grader came up to me, pointed to a kindergartener who was "reading" a book upside down, and said, "Teacher, do you think you can teach HIM to read like me?" I assured him that I felt pretty confident that I could.