1 1/9 is 10/9, because we multiply the whole number 1 by the denominator (bottom) of the fraction and add the result to the numerator (top) of the fraction part making it 10, making the improper fraction 10 over 9. That's a division, 10 divided by 9. 9 goes into 10 once (the whole number 1) remainder 1, which is 1/9 or one ninth. The nearest whole number is therefore 1. Rounding to the nearest whole number just means: is 1 1/9 nearer to 1 or 2? If the remainder when 9 was divided into 10 had been more than half of 9, we would have rounded to whole number 2. How many ninths would cause us to round to 2? The number 4 is less than half of 9, so we would still be nearer to 1 than 2; but if we had 5 or more (5, 6, 7 or 8) we would round to 2.