the general rule for estimating is to look at the digit to the right of the digit you want to estimate. Estimating or rounding to the nearest whole number means looking at the digit to the right of the decimal. if you see a digit greater than 5,round up, an if it's less than 5, round down. we would go to the right of 18.3 which would be (6.37), so we're going to to round that to the nearest whole number which would be 7 because it's more than 5. this shows how you estimate 18.3 an (6.37) hope this helps have a good day♡
