Question

1. what is $12\frac{11}{18}$ rounded to the nearest whole number? (7-4)

a 11
b 12
c 13
d 18

1. serafina can choose between two

Explanation:

Step1: Analyze the fraction part

The mixed number is \(12\frac{11}{18}\). We need to look at the fractional part \(\frac{11}{18}\). To round to the nearest whole number, we compare the fraction to \(\frac{1}{2}\) (since if the fraction is greater than or equal to \(\frac{1}{2}\), we round up; otherwise, we round down).
First, find \(\frac{1}{2}\) with denominator 18: \(\frac{1}{2}=\frac{9}{18}\) (because \(18\div2 = 9\), so multiply numerator and denominator of \(\frac{1}{2}\) by 9: \(\frac{1\times9}{2\times9}=\frac{9}{18}\)).

Step2: Compare the fractions

Now, compare \(\frac{11}{18}\) and \(\frac{9}{18}\). Since \(11>9\), \(\frac{11}{18}>\frac{9}{18}\) (which is \(\frac{1}{2}\)).
When the fractional part of a mixed number is greater than or equal to \(\frac{1}{2}\), we round the whole number part up by 1. But wait, the whole number part here is 12, and the fraction \(\frac{11}{18}\) is greater than \(\frac{1}{2}\)? Wait, no, wait: Wait, \(\frac{11}{18}\) is approximately \(0.611\), and \(\frac{1}{2}=0.5\). So \(0.611>0.5\), so we should round up? Wait, no, wait the mixed number is \(12\frac{11}{18}\), so the whole number part is 12, and the fraction is \(\frac{11}{18}\). Wait, but wait, maybe I made a mistake. Wait, \(\frac{11}{18}\) is less than 1, so when rounding \(12\frac{11}{18}\) to the nearest whole number, we check if the fraction is more than or equal to \(\frac{1}{2}\). Since \(\frac{11}{18}>\frac{9}{18}=\frac{1}{2}\), we round up the whole number part. Wait, but 12 + 1 = 13? Wait, no, wait: Wait, \(12\frac{11}{18}\) is between 12 and 13. The distance from 12 to \(12\frac{11}{18}\) is \(\frac{11}{18}\), and the distance from \(12\frac{11}{18}\) to 13 is \(1 - \frac{11}{18}=\frac{7}{18}\). Since \(\frac{11}{18}>\frac{7}{18}\), so it's closer to 13? Wait, no, wait, no: Wait, when rounding to the nearest whole number, the rule is: if the fractional part is \(\geq\frac{1}{2}\), round up; else, round down. Since \(\frac{11}{18}\approx0.61>0.5\), so we round up 12 to 13? Wait, but wait, let's calculate \(12\frac{11}{18}\) as a decimal: \(11\div18\approx0.611\), so \(12 + 0.611\approx12.611\). Rounding 12.611 to the nearest whole number: look at the tenths place, which is 6, which is greater than 5, so we round up the ones place: 12 + 1 = 13. Wait, but the options are A 11, B 12, C 13, D 18. So the correct answer should be C? Wait, but wait, maybe I made a mistake. Wait, \(\frac{11}{18}\) is less than \(\frac{1}{2}\)? Wait, no, \(\frac{1}{2}\) is 0.5, \(\frac{11}{18}\) is approximately 0.61, which is more than 0.5. So yes, we round up 12 to 13. So the answer is C.

Answer:

C. 13