How to Round Numbers

Series Summary

Mathematics is the body of knowledge and the academic discipline that studies concepts such as quantity, structure, space and change. Mathematics education is a term that refers both to the practice of teaching and learning mathematics, as well as to a field of scholarly research on this practice. At different times and in different cultures and countries, mathematics education has attempted to achieve a variety of different objectives, including the teaching of basic numeracy skills to students and teaching both practical and abstract mathematics. In this free video series on math, an experienced math teacher explains math problems and history. Get information on who invented numbers, famous mathematicians and famous female mathematicians. Learn how to solve algebra equations, division problems and radicals. Get tips on factoring equations and dividing polynomials. Improve math skills with the help of these free videos.

Video Transcript

"So how does one round numbers? Hi, I'm Jimmy Chang, I've been teaching college math for 9 years and we're here to give you a few tips on how to round numbers. Now there's going to be a pattern involved and once you see the pattern, rounding becomes pretty straightforward after that. So here's a couple of quick examples for you. First we're going to talk about rounding to the nearest 10. Suppose you have let's just say the number 37. Now rounding to the nearest 10 that means it's either going to go round down to 30 or round up to 40. Now because we round to the nearest 10, your focus is going to be on the next digit over. So our focal point is on the number 7. Now a big rounding rule is if the number is 5 or more, you round up. But if it's less than 5, you round down. Now obviously because the 7 is 5 or more, that means that the 37 gets rounded to 40. Now here's another example. Suppose you have 149. You want to round to the nearest 100. It will either round up to 200 or round down to 100. Now because we round to the nearest 100, again you simply look at the next place over. Now because the digit is 4, it falls in the less than 5 category which says you must round down. So 149 rounds down to 100. And last but not least, suppose you have let's just say 3500, you want to round to the nearest thousand. That means the 3500 is either going to round up to 4000 or round down to 3000. Again, since you're rounding to the nearest 1000, look over at the next digit which is the 5. But as you can see, the 5 is part of the 5 or more criteria and if it's 5 or more you round up. So the 3500 rounds to 4000. So I'm Jimmy and this has been a glimpse on how to round numbers."