Rounding

Learning Objectives Round two-digit numbers to the nearest 10. Round three-digit numbers to the nearest 10. Round three-digit numbers to the nearest 100. Use a number line to visualize and perform rounding. Identify the 'rounding digit' and the 'look-next-door' digit in a number. Apply the '5 or more, raise the score' and '4 or less, let it rest' rules. Explain that a rounded number is an estimate, not an exact number. Ever wonder how many jellybeans are in a giant jar? 🍬 Rounding helps us make a super smart guess! In this lesson, you'll learn how to round numbers to make them simpler and easier to work with. Rounding is a super skill for making quick estimates, like guessing the cost of your toys or the number of kids in the...

TermDefinitionExample RoundingMaking a number simpler but keeping its value close to what it was. It's like finding the 'nicest' number nearby.The number 78 is close to 80, so we can round 78 to 80. EstimateA smart guess that is close to the real answer.If you have 23 crayons, you can say you have 'about 20'. The number 20 is an estimate. Nearest TenThe multiple of 10 (like 10, 20, 30, 40...) that a number is closest to.For the number 43, the nearest ten is 40. Nearest HundredThe multiple of 100 (like 100, 200, 300...) that a number is closest to.For the number 281, the nearest hundred is 300. Rounding DigitThe digit in the place value you are rounding to.When rounding 146 to the nearest ten, the '4' in the tens place is the rounding digit. Look-Next-Doo...

The '5 or More' Rule (Rounding Up) If the look-next-door digit is 5, 6, 7, 8, or 9, you round up. When the digit to the right of your rounding digit is 5 or more, you 'raise the score' by adding one to the rounding digit. All digits to the right of the rounding digit become zeros. The '4 or Less' Rule (Rounding Down) If the look-next-door digit is 0, 1, 2, 3, or 4, you round down. When the digit to the right of your rounding digit is 4 or less, you 'let it rest' by keeping the rounding digit the same. All digits to the right of the rounding digit become zeros.