Rounding and estimating
We can use significant figures to get an approximate answer to a problem.
We can round off all the numbers in a maths problem to 1 significant figure to make 'easier' numbers. It is often possible to do this in your head.
Find a rough answer to
We first round off both numbers to 1 significant figure (s.f.):
19.4 = 20 (1 s.f.)
0.0437 = 0.04 (1 s.f.)
So we now need to make the denominator a whole number. We can do this by multiplying both 20 and 0.04 by 100.
Divide everything by 4.
The real answer to 19.4 ÷ 0.0437 = 443.9359... So this was a good estimate.
Try this one. Remember, the working you do is just as important as the answer.
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