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Week 10 · Springs and Click Pens

Thursday

Test the spring
// A spring pushes back
⏱ about 15 min

Thursday: Test the Spring

Rocket lines up the pen spring next to a ruler.

"Let us measure it!" he says.

Raven asks, "What do you notice when we squeeze it?"

Nova glows a number on the ruler. "Would you like a hint? Measure twice."

A fair test

Today we measure the pen spring.

First, measure it resting.

Then squeeze it gently and measure again.

A fair test measures the same way each time.

  • The pen spring from yesterday
  • A ruler
  • The cup for the parts
  • Paper and a pencil
Safety first
Hold the spring low over the tray so it cannot fly.
Squeeze gently. Do not bend the spring sideways.
Small parts stay away from younger siblings and mouths.
  1. Set the spring on the ruler.
  2. Count how many marks long it is.
  3. Write the number in your table.
  4. Squeeze the spring gently with two fingers.
  5. Count the marks again.
  6. Write that number too.
  7. Let go. Does it go back to the first number?
SpringMarks long
Resting
Squeezed
After letting go
WHAT HAPPENED?
  • Read the question.
  • Tap your answer.
When you squeezed the spring, what happened to its length?
You let go. What should the spring do?
Why measure the same way each time?

Put the pen back together

  1. Slide the spring onto the ink tube.
  2. Put the ink tube into the barrel.
  3. Put the button back on top.
  4. Twist the two barrels back together.
  5. Click it. Does the tip come out?
SentenceTrue or false?
A squeezed spring is shorter than a resting spring.?
A fair test measures a different way each time.?
The spring goes back on the ink tube.?
WHY THIS EXERCISEMeasuring the same way each time makes your test fair.
For a grown-up
Help line up the spring on the ruler.
If a part is lost, check the cup and the tray.
Praise careful measuring, even if the numbers are close.
REBUILD CHECK
  • Read the question.
  • Tap your answer.
What goes onto the ink tube first?
The tip does not come out after the rebuild. What now?
What did Nova hint in the story?
Draw your spring on the ruler, resting and squeezed.

You tested a spring and rebuilt a pen. Amazing!

Tomorrow, you explain how a click pen works.

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