Two Methods of Decrease: Walkthrough and Strategy

Section role: supports the 'Mapping the Decrease' section while the teacher guides the class to compare results from the water tank challenge and formalize the two calculation strategies. Slides: (1) Title — 'Mapping the Decrease: Two Ways to Solve'; (2) Defining Dynamic Change — bullets: what dynamic change means, introducing 'Remaining Balance', connecting back to the school garden water tank; (3) Method 1: Sequential Subtraction — bullets: step-by-step breakdown using 200 minus 45, 155 minus 30, and 125 minus 50; (4) Method 2: Sum of Decreases — bullets: combining all uses first (45 plus 30 plus 50 equals 125) then subtracting from 200; (5) Number Line Visualization — bullets: visual representation of the number line moving backward in steps versus a single big jump; (6) Closing slide: 'Which method do you prefer and why?' — sets up the individual snack shop math activity that follows.

Lara from Teachy