Two pieces become a train
Join two small lengths and count every unit once. Explore a model, explain the relationship, and try it with physical materials.
450 lesson drafts and nine original starter guides. Explore number relationships, fractions, sorting, patterns, shapes, and more. Try three complete free sample lessons. A paid adult account opens all teaching guides, printable PDFs, and learning tools.
Choose by readiness and prior teaching. Grade labels are starting points. How to choose a starting point
Showing 1–12
Join two small lengths and count every unit once. Explore a model, explain the relationship, and try it with physical materials.
Align starting ends before deciding which train is longer. Explore a model, explain the relationship, and try it with physical materials.
Notice that reversing two parts preserves their total length. Explore a model, explain the relationship, and try it with physical materials.
Fill a visible length gap with a matching rod. Explore a model, explain the relationship, and try it with physical materials.
Replace a rod by smaller parts without changing the whole. Explore a model, explain the relationship, and try it with physical materials.
Transfer one unit between two parts while preserving the total. Explore a model, explain the relationship, and try it with physical materials.
Connect a spoken before-and-after story with two visible parts. Explore a model, explain the relationship, and try it with physical materials.
Distinguish the number of objects from the length they cover. Explore a model, explain the relationship, and try it with physical materials.
Make equal small groups by repeating one rod. Explore a model, explain the relationship, and try it with physical materials.
Collect different two-part solutions using objects and adult recording. Explore a model, explain the relationship, and try it with physical materials.
Connect a rod construction with a counted quantity through ten. Explore a model, explain the relationship, and try it with physical materials.
Predict a one-unit increase from a known total. Explore a model, explain the relationship, and try it with physical materials.