Hello @teacheryuyu,
Thank you for your comment :) I am not sure how one would go about talking to young learners about acceptance, being in the present and awareness. But, I am certain that motivating them to exercise their attention and focus is a healthy thing, which actually could be done in a "fun" way, in a group. You would just have to guide them through the three minutes while instructing them to breath in or breath out :) as another reader suggested, they could even do it with their eyes open! :)
All the best.