Counting and Finding Missing Numbers up to 120

Khan Academy

This video serves as a practical, guided practice session for counting and identifying whole numbers beyond 100, specifically focusing on the range up to 120. The narrator walks through four distinct exercises using digital interactive tools: filling in missing numbers in a sequence, identifying numbers that come "before" a target number, and locating missing values within a full 1-120 number grid. The approach emphasizes pattern recognition, explicitly teaching students that the counting patterns they learned for single digits (e.g., 4 comes before 5) apply directly to larger numbers (e.g., 104 comes before 105). The key themes explored are number sequencing, the concept of "before and after," and the structure of the base-10 number system. By using a visual 120 chart, the video highlights how numbers repeat patterns in the ones and tens places as they cross the 100 threshold. The narrator's logic helps demystify three-digit numbers by connecting them back to familiar one- and two-digit sequences. For educators, this video is an excellent resource for bridging the gap between counting to 100 and counting to 120, a specific standard in early elementary math. It models the internal monologue a student should use when solving these problems ("If 6 follows 5, then 106 follows 105"). Teachers can use this as a warm-up for a math block, a model for how to use a 120 chart, or as a remediation tool for students struggling with the transition to three-digit numbers.