Your skull protects your brain. Ribs protect heart and lungs.
A joint is where two bones meet.
Each bone has a shape that fits its job.
A model shows how something works.
◇ FAMILY FINGER MODEL
A grown-up cuts a straw into three short pieces. Lay the pieces in a line with small gaps. Tape a string inside the tip piece. Thread the string through all three pieces. Hold the bottom piece. Gently pull the string. Does your model finger bend at the gaps?
Safety first
A grown-up does all the cutting. Keep string away from necks. Nothing goes in your mouth.
For a grown-up
Ask: where did the model bend? Ask: what would you change to make it better? Celebrate a model that does not work yet. That is engineering!
MODEL CHECK
Read the question.
Tap your answer.
Where should the model finger bend?
Your model will not bend. What now?
Draw your finger model bending.
You built a real model, engineer!
Next week, you will find out how muscles move bones.