6.666
That depends with what precision you want to round it. When rounded to the nearest whole number, the answer is 267. If rounded to the nearest 10, it is 270. If rounded to the nearest hundred, 300. If rounded to the nearest thousand, the answer is zero.
71956.00
221.0
9837.0
9.2 or, if you want to indicate that it is to the nearest hundredths, 9.20
Digits to the right of the decimal point represent, in order from the point: tenths; hundredths; thousandths; ten-thousandths; hundred-thousandths etc etc. You want your figure rounded to 4 digits and normal practice is to round 5 upwards so the answer would be 0.7188
76.5 is already rounded to the nearest tenth, which is more rounded than to the nearest hundredth. If you want to indicate that the number is accurate to the nearest hundredth, then write it as 76.50 otherwise leave it as it is.
That depends whether you want to round it to the nearest thousand or thousandth. Rounded to the nearest thousand, 4.536 is approximately equal to 0. The number is already rounded to the nearest thousandth.
1.1 The nearest tenth is the rounded-up value 1.10 = 1.1
11.50
1.0