Visualizing Subtraction with Place Value Blocks

Khan Academy

This video provides a clear, visual demonstration of subtracting a single-digit number from a two-digit number using place value concepts. The narrator uses digital manipulatives—specifically base-ten block drawings—to represent the number 46, decomposing it into four tens and six ones. This visual approach helps students concretely understand what the abstract numbers represent before any operations are performed. The core theme of the video is understanding subtraction through the lens of place value. By physically crossing out four 'ones' blocks from the original six, the video demonstrates that when subtracting single digits (without regrouping), the operation only affects the ones place while the tens place remains unchanged. This reinforces the concept that digits in different positions have specific values and function independently in simple operations. For educators, this video is an excellent tool for bridging the gap between concrete manipulatives and abstract equations. It is particularly useful for introducing non-regrouping subtraction in 1st or 2nd grade. Teachers can use this to model how to draw 'quick tens and ones' to solve problems, showing students a strategy they can use even without physical blocks. The video explicitly connects the visual act of taking away blocks to the numerical procedure of changing the digit in the ones place.