Rounding Up or Down to the Nearest Ten

Introduction

• Invite students to bring their math journals and a pencil to the class meeting area.
• Tell them to place their supplies on the floor next to them.
• Tell the students that today they're going to learn how to round a number to the nearest ten. Let them know that rounding is a way of estimating, where one makes a number less precise but easier to work with.
• Before starting do a short review of place value, in particular the “place” of a digit in a number. On the board write the following "Place: The position of a digit in a number"
• Follow that up by writing "10,000s 1,000s 100s 10s 1s" underneath.
• Let the students know that the place of the digits is important in rounding.
• Tell them in the case of rounding to the Nearest Tens, the ones place is of particular importance. Share the following Rules with the students about rounding to the nearest ten: a. If the digit in the “ones” place is between 0 and 4, round down to the nearest ten. b. If the digit in the “ones” place is between 5 and 9, round up to the nearest ten.
• Let the students know that the rules stand regardless of the size of the number involved.
• Next, come up with a few numbers to model rounding to the nearest ten.