In this lesson, students learn to round whole numbers to the tens place and the hundreds place. The process of rounding is illustrated using a number line. Students learn that rounding to the tens place means writing the number using the number of tens that is closest to the number, without using a digit in the ones place. Rounding to the hundreds place means writing the number using the number of hundreds that is closest to the number, without using digits in the tens or ones place.
This lesson is designed to build fluency in adding three-digit numbers. Earlier, students have learned to add three-digit numbers using the standard algorithm. In this lesson, students use that knowledge to get additional practice adding these numbers.
This lesson is designed to build fluency in subtracting three-digit numbers. Earlier, students have learned to subtract three-digit numbers using the standard algorithm. In this lesson, students use that knowledge to get additional practice subtracting three digit numbers, with special emphasis given to problems in which the digit in the tens place and/or the hundreds place is a zero.