In earlier lessons, students learn to add 3-digit numbers that require regrouping, using place value concepts. When addition in a given place value results in a number that is greater than 10, students learn to make a ten in the next column to the left.
In this lesson, they extend their knowledge to add numbers with 4 digits that require regrouping. Special attention is given to situations in which the two numbers added have a different number of digits.
In earlier lessons, students learn to subtract 2- and 3-digit numbers from 3-digit numbers using place value concepts, including situations that require regrouping. When subtraction in a given place value requires regrouping, students learn to break a ten in the next column to the left.
This lesson extends what they learn in those lessons to numbers with 4 digits in the minuend and 3 or 4 digits in the subtrahend, including situations in which regrouping is required.
Special attention is given to situations in which the minuend includes one or more zeros.