Babies: an infant reaches for a rattle just out of reach. You wait instead of handing it over, name what they are doing, and move it slightly closer only when they have tried a few times. The waiting is the intentional part.
Toddlers: a toddler keeps filling a bucket that tips over. You offer a scoop and a flatter bucket, and say "Let's see if this one stays up." You are giving them a new way to test the same idea, not solving it for them.
Preschoolers: a group argues about whose tower is tallest. You ask "How could we find out?", bring string and blocks, and let them decide how to measure. Tomorrow you plan a measuring experience because of what you saw today.