Hundredth is the 2nd decimal place away from the decimal point. In 13.689, 8 is in the hundredths place. When you round tho, you don’t just take the number that’s already in the hundredths place, you have to look at the number directly after it. Since 9 is directly after it, in the thousandths place, and it’s part of the numbers 5-9 which signify to round up, you have to round the 8 up to 9. So in the end, the rounded number would be 13.69