Adding Multiples of Ten to Two-Digit Numbers

MatholiaChannel

This educational video provides a clear, visual demonstration of adding multiples of ten to two-digit numbers, specifically focusing on sums within 50. Through three distinct examples, the narrator guides students on how to decompose numbers into tens and use a number line to "count on" by tens. The video progresses from concrete representations using base-ten cubes to more abstract numerical problems. The content emphasizes key arithmetic concepts such as place value, decomposing numbers (e.g., identifying that 30 is "3 tens"), and using number lines as a calculation strategy. By showing the relationship between physical quantities (cubes) and their positions on a number line, the video helps bridge the gap between concrete manipulatives and abstract mental math strategies. For classroom application, this video is an excellent tool for introducing or reinforcing the "jump strategy" for addition. It is particularly useful for visual learners who benefit from seeing the physical quantity of numbers alongside the symbolic notation. Teachers can use this video to model how the ones digit remains constant while the tens digit increases, laying the groundwork for mental math fluency and understanding place value patterns.