Concept 3 of 6
Estimate, Then Measure
Today's big idea
Guess the length first, then measure to see how close you were.
Guess about 10 cm, measure 12 cm — close.
How it works
👀 What's going on?
Before you measure, take a smart guess. Then check it.
💡 Here's the trick
An estimate is a good guess. Guess the length first, then measure to see how close you were.
You guess a marker is about 10 cm. You measure it: 12 cm. Close!
✍️ Try it
You guess a spoon is 15 cm and it measures 14 cm. Were you close? → yes.
⚠️ Watch out
An estimate is a guess, not the exact answer, so always measure to be sure.
Watch me solve one
Quanta solves it
“Watch how I think through one of these — then you try.”
THE PROBLEM
“You guess a spoon is 8 cm. It measures 9 cm. Were you close?”
- 1
Compare guess and measure
Guess 8, measured 9.
- 2
How far off?
Only 1 cm apart, so the guess was close.
- 3
Answer ✓
Yes — a close guess
Now you try one — same steps, different story 👇
See it in action
⚡ Time to play!
A close guess is within a couple of centimetres.
guess
10 cm
measured
12 cm
Was the guess close or far?
Quick check
✅ VERIFICATION
A good estimate for the width of your hand is about…
⚡ Finish the activity above first to answer.
Keep going!
Up next: Comparing Lengths
Measure both, then the bigger number wins.