Lab: Bar-Model Visualizer
Draw the story as bars: totals split into parts, comparisons reveal differences. If you can draw it, you can solve it.
Bar model builder
45 + 28 = 73
Try it
Challenge: Maya has 45 stickers, Leo has 28. How many more does Maya have?
Switch to the comparison model, set the sliders, then type the difference.
What to notice: the total model answers “how many altogether” (add); the comparison model answers “how many more / fewer” (subtract the smaller from the bigger).
Which model?
Total model: parts combine into a whole — “altogether”, “in all”, “total”.
Comparison model: two amounts side by side — “how many more”, “how many fewer”, “difference”.