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Week 11 · Lift It

Thursday

Move the fulcrum
// A lever or pulley that lifts a small load
⏱ about 20 min

Thursday: Move the Fulcrum

"Seven push coins to lift six load coins," Nova reports.

Rocket scratches his head. "That is a lot of effort."

Raven taps the marker. "What do you notice? It is right in the middle."

Nova blinks. "Would you like a hint? Remember Tuesday."

VersionWhere is the fulcrum?Push coins needed
Rocket version 1In the middle7

Find the change

The fulcrum was in the middle.

It took more push coins than load coins.

Tuesday we learned: load close to the fulcrum takes less effort.

The crew will change one thing: move the fulcrum toward the load.

READ THE TABLE
  • Read the question.
  • Tap your answer.
How many push coins did version 1 need?
ONE FAIR CHANGE
  • Read the question.
  • Tap your answer.
Which plan changes only one thing?
Which way should the fulcrum move?
PLAN THE NEXT TEST
  • Tap a card.
  • Then tap its spot.
1First
2Next
3Then
4Last
Draw your lever with the fulcrum moved.

Make a guess

Raven guesses the new lever will need fewer push coins.

Her reason: Tuesday's rule about the fulcrum.

Friday's test will check her guess.

LEVER DETECTIVE
  • Read the question.
  • Tap your answer.
Version 1 needed 7 push coins to lift 6 load coins. Which is more?
What is Raven's guess?
What stays the same in the new test?
IdeaTrue or false?
Rocket gave up on the lever.?
A guess should have a reason.?
The crew will move the fulcrum toward the push cup.?
WHY THIS EXERCISEGood guesses come from what we already learned.

You used what you learned to plan a fix!

Tomorrow, we test version 2.

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