Converting square units: why 1 m² is not 100 cm²
1 m = 100 cm, so 1 m² = 100 cm²… except it's 10,000. Area scales with the square of the conversion factor.
Why it happens
The linear conversion is memorized as a number (×100), and numbers don't carry dimensions. The 'squared' in cm² silently applies to the unit, not your factor.
See the trap
A poster is 0.5 m² . How many cm² is that?
0.5 × 100 = 50 cm².
0.5 × 100² = 5,000 cm².
How to actually fix it
- 1Write the conversion as a fraction and square the whole fraction for areas.
- 2Volumes cube it (1 m³ = 10⁶ cm³).
- 3Sanity-check magnitude: smaller units always mean bigger numbers.
Practice this trap · 2 real questions
Each of these is a question from the free bank that turns on the mistake above — the trap is the reason its wrong answer looks right. Easiest first.
FAQ
Where does the SAT hide this?
Density, paint-coverage, and map-scale problems — anywhere an area crosses a unit boundary.
How do I stop repeating this mistake?
Reading the explanation isn't enough — your brain needs to beat the trap on a fresh question. Practice the skill in the kaoshen.co question bank: miss one and it is logged with the exact error, then brought back to you three days later and again after fourteen.
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