67.345g rounded to the nearest 1.0 whole number

Look at the tenths place.

If it's less than 5, round down.

If it's greater than 5, round up.

If it's equal to 5. look at the next digit and round that to see if you should round up or down. Then, if it's the last digit, round up.

3 is less than 5, so round down.

67 - 1 = 66 grams.

67.0 or 67 is to the nearest whole number