Question

1. if the digit to be dropped is less than 5,

ound down\ and if it is more than 5,
ound up\. if the dropped digit is exactly 5, round up if the preceding number is odd, and round down if the preceding digit is even. if any nonzero digits follow the dropped 5, round up.
round the following to 1 decimal place:
85.4500
85.45061
85.5500

85.550004
85.651423
85.65000
practice problems:
perform the following calculations and report the answer to the correct number of significant figures
6.70 + 11.9 + 251.875 - 89.552 =
2300/4.75 =
2.300/4.75 =
(100.0 -85.457)

Explanation:

Step1: Round 85.550004 to 1 decimal

Dropped digit=5, nonzero digits follow → round up.
$85.550004
ightarrow 85.6$

Step2: Round 85.651423 to 1 decimal

Dropped digit=5, nonzero digits follow → round up.
$85.651423
ightarrow 85.7$

Step3: Round 85.65000 to 1 decimal

Dropped digit=5, preceding digit=6 (even) → round down.
$85.65000
ightarrow 85.6$

Step4: Calculate sum/difference with sig figs

Add/subtract first, round to least decimal places (1 from 11.9).
$6.70 + 11.9 + 251.875 - 89.552 = 180.923
ightarrow 180.9$

Step5: Calculate 2300/4.75 with sig figs

Divide, round to 2 sig figs (from 2300).
$\frac{2300}{4.75} = 484.2105...
ightarrow 4800$

Step6: Calculate 2.300/4.75 with sig figs

Divide, round to 3 sig figs (from 4.75).
$\frac{2.300}{4.75} = 0.4842105...
ightarrow 0.484$

Step7: Calculate (100.0-85.457) with sig figs

Subtract, round to 1 decimal place.
$100.0 - 85.457 = 14.543
ightarrow 14.5$

Answer:

Rounded values to 1 decimal place:
$85.550004 = 85.6$
$85.651423 = 85.7$
$85.65000 = 85.6$

Practice Problems answers:
$6.70 + 11.9 + 251.875 - 89.552 = 180.9$
$2300/4.75 = 4800$
$2.300/4.75 = 0.484$
$(100.0 - 85.457) = 14.5$