During the past six weeks, we have focused on counting and comparing numbers within 1,000. In their first deep exposure to three-digit numbers, have friends built, counted to, and compared three-digit numbers.
By the end of second grade, students should be able to start at any number within 1,000 and count on by ones, fives, tens, and hundreds. They should also be able to read and name the values of the digits in three-digit numbers.
Friends modeled three-digit numbers in different ways as they developed their understanding of how numbers group in tens.
To make the number 256, Million counted by tens to 250 and then counted six ones by ones.He then grouped the tens into hundreds to make two groups of 100, five groups of ten, and six loose ones. He put the ten tens into ziplock bags to distinguish them from the loose tens, naming them “hundreds”.Almoni and Ashley adopted this strategy to model 325. Ashley added labels both to name the groups and to show her counting strategy. She put a “100” label on each bag to name it a hundred bag. She labeled each stick of ten with “10” to name it a ten.Almoni counted by 100s and then on by tens and ones to find the total number of cubes.Ashley added a second set of labels to show how they counted. 100, 200, 300, 310, 320, 325.This week, they transferred their models to paper, drawing boxes and lines, and adding labels to represent the different values of each digit in a three-digit number.