#### Answer

a)3.1
b)3.142

#### Work Step by Step

To round to the nearest tenth, inspect the hundredths digit. If 5 or greater, round up.
$3.1\underset\uparrow416$
do not round up
$3.1416\approx3.1$
To round to the nearest thousandth, inspect the ten-thousandths digit. If 5 or greater, round up.
$3.141\underset\uparrow6$
round up
$3.1416\approx3.142$