Chemistry / Unit 1 Chem 0142 short lesson, about 20 seconds
Round-Half-to-Even Rule
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The idea
When the digit dropped is exactly 5 with nothing after it, round to whichever neighboring digit is even, not up.
In practice
92.85 rounds down to 92.8, since 8 is already even, while 0.90275 rounds up to 0.9028, since 7 is odd and 8 is even.
Where people slip
The "round 5 up" rule from grade school does not apply here — it introduces bias.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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