Round to the nearest whole number means round the tenth digit to the one digit, so
Divide 1 by 2
1/2 = 0.5, so we will add 0.5 and subtract 0.5 from 7
7 - 0.5 = 6.5
7 + 0.5 = 7.5, so
[tex]6.5\text{ }\leq\text{ 7 mm <7.5}[/tex]You can choose any number between them
[tex]6.5\approx\text{ 7}[/tex][tex]7.49\approx\text{ 7}[/tex]