About This Lesson
Lessons include: Partition three-digit numbers in different ways; Round to the nearest 100; Estimate by rounding to the nearest 100 and check using the inverse operation (on a number line); Estimate by rounding to the nearest 10 and check by using the inverse operation (column method); Add or subtract 99 or 90 by adjusting; Add or subtract 98 or 80 by adjusting; Add a near multiple of 100 to a three-digit number by adjusting; Subtract a near multiple of 100 from a three-digit number by adjusting; Add near doubles by adjusting; Complete four-layer addition pyramids
