Thinking algorithmically. For example, sequence, selection, and repetition. Compare a task to something a computer would do. Find humor in repeating an operation, or taking an instruction literally. Multiplication as repeated addition.
Problem decomposition. Reward attempts to spell a word based on what they know (phonetics). Show a word is made of letters, and sounds combine letters, and solving the smaller piece helps to get the larger whole. "You can figure it out if you can break things down small enough to something you can handle."
Abstraction. When something funny happens or "what if" is asked, imagine a world where it's possible. Ask what would be true in that world; what is discarded to simplify, and what is kept to define constraints.
Data structures. Make adhoc notebooks out of stapled paper. Fold and cut index cards. Show page numbers as a way to "address" other pages. When a container is full, mention overflow.
Composition. Use a copy machine to compose a scene. Copy an object, copy that plus another object, and repeat.