CPU - smart, but forgetful. Can't hold even two things in memory, so it needs instructions
ALU
Create boxes for registers.
Not enough boxes? Borrow boxes from other people - memory - it's slow, but you have a lot.
Addresses
STORE [address 1], box1
LOAD box2, [address 2]
Pipeline
Having to pipeline the CPU may be too hard for children, however they should get the idea of pipeline on a different example, such as making a peanut butter sandwich with limited resources (knives, peanut butter jars)
Have kids pipeline a process. Have them deal with the conflict