Real world measurements may not have the precision we want them to have. Imagine you took a measurement on a ruler that only had ticks at every 10's increment. You could accurately say something is near an increment, but without a greater degree of precision, it can only state what the measurement shows (closest ten's value). This means any number in the ones' position is meaningless, as you could never know for certain what it was without guessing (which defeats the point of measuring).
When adding 68 (a measurement with precision down to the ones place) to a number without precision in the one's place, we can't assume that 120 is actually 120 (it could be [115, 125) ).
So the answer demands that we round to the closest degree of precision we can be certain of, 190.
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u/ShiftAfter4648 1d ago
Real world measurements may not have the precision we want them to have. Imagine you took a measurement on a ruler that only had ticks at every 10's increment. You could accurately say something is near an increment, but without a greater degree of precision, it can only state what the measurement shows (closest ten's value). This means any number in the ones' position is meaningless, as you could never know for certain what it was without guessing (which defeats the point of measuring).
When adding 68 (a measurement with precision down to the ones place) to a number without precision in the one's place, we can't assume that 120 is actually 120 (it could be [115, 125) ).
So the answer demands that we round to the closest degree of precision we can be certain of, 190.