How often do we give kids opportunities to come back to class with stories about what God has done for them during the week (or just to share with you as a grown-up or with family and friends)? Does it put kids "on the spot" needlessly, does it make some kids feel more special or less special than someone else or does it grow their faith?
Sometimes it's answered prayer.
Sometimes it's just growing eyes to see or ears to hear something to be thankful for.
Sometimes you think, "Wow! Look at what God did! It could have been worse..."
Growing thankfulness without one of your kids rolling their eyes because you're thankful for EVERYTHING! and it starts to sound contrived. And we should be thankful for everything . . . but you know what I mean. There are things God does that we couldn't possibly do. There things that could've happened for any number of reasons but why not give God the glory? (even if you don't always say it out loud)
If giving and serving in secret is the name of the game. Consider keeping a box in the corner of the room (or just inside or outside the door) during the school year where kids or parents can drop a piece of paper with a way they've blessed or been blessed by someone (no names) - something they've found particularly meaningful. Near the end of the term (maybe those last weeks before summer break) read a few at the end of each class or let the kids pull one out and read it. Maybe you'll want to do it more often than that. Use them as a worship tool for praise. Use them to inspire those random (secret) acts of kindness. The scriptures have told us for generations to remember what God does and praise Him.