Webinars SET A - Grade 3-4 - Sunday@3:15-4:15pm EST-Recording Webinar 3

Video Transcription

Video Summary

This Math Kangaroo webinar for grades 3-4 focused on the strategy of “Making an Organized List” to solve math problems. The moderators, Sarah and Avi Abhinav, guided students through problems emphasizing listing possibilities, casework, and combinatorial logic.<br /><br />The session began with identifying shapes from a set and progressed to counting three-digit numbers formed with specified digits, carefully excluding invalid ones. Students then tackled a painted cube problem, determining how many smaller cubes had exactly two painted sides, illustrating spatial reasoning.<br /><br />Next, they explored arranging toys with placement restrictions, using examples of where a car, ship, airplane, and ball could be positioned on a shelf. Combinatorial methods and listing were combined to find the count of valid arrangements.<br /><br />A digit counting problem required listing pages containing the digit five to find the maximum page number in a book with exactly 16 digits five appearing. The concept of careful enumeration and constraints was highlighted here.<br /><br />A botanical garden path problem showed using labels and casework to count distinct routes under constraints of walking each path only once, yielding a total of eight possible paths.<br /><br />A lock-opening problem focused on counting minimum locks to open to access a certain number of gold coins, demonstrating work from top-down or bottom-up approaches equally valid.<br /><br />Bonus problems included calculating all possible scores from archery targets and sandwich combinations with fixed bread, meat, and vegetable options, illustrating the importance of recognizing order does not matter in some selections (combinations).<br /><br />Throughout, the importance of organized listing, spotting redundancies, splitting into cases, and using patterns was emphasized to manage complexity and efficiency. Students were encouraged to practice these strategies through contests and use available discount codes to improve skills for Math Kangaroo challenges.

Keywords

Math Kangaroo

organized list

casework

combinatorial logic

spatial reasoning

digit counting

botanical garden paths

lock-opening problem

archery scores

combinations