Waiting for answer This question has not been answered yet. You can hire a professional tutor to get the answer.

QUESTION

# How do you use a calculator to evaluate the expression log12 to four decimal places?

log 12 ~~ 1.0792

Since I remember (as is useful to remember):

log 2 ~~ 0.30103

log 3 ~~ 0.47712125

I can calculate:

log 12 = log (2*2*3)

color(white)(log 12) = log 2 + log 2 + log 3

color(white)(log 12) ~~ 0.30103 + 0.30103 + 0.47712125

color(white)(log 12) ~~ 0.60206 + 0.47712125

color(white)(log 12) ~~ 1.07918125

If you request log 12 on a calculator, you will get a similar approximation.

If we truncated this to 4 decimal places then we would get:

1.0791

but the following digit is 8 >= 5, so in order to round the value to 4 decimal places we need to round up the final digit 1 to 2 to get:

log 12 ~~ 1.0792

color(white)()Footnote

If you remember good approximations for log 2 and log 3 then you can calculate approximations to log n for n in { 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20,... }, i.e. any positive integer whose only prime factors are 2, 3 or 5.

That seems to me to be good value for the sake of remembering a couple of numbers.