Direct Measurement with Non-Standard Units
Warm-up
How wide is your desk? Measure it with your hand. Students measure and report. Why did we get different answers? The desk did not change. Let the discrepancy surface naturally. What would happen if we all used the same-sized thing to measure?
Explore
Partner measurement: each pair receives one linking cube and one ribbon. They must measure the ribbon by iterating the cube (moving it end-to-end). Record: how many cubes long? All pairs share results. Since the cube is uniform, results should match. Compare to the hand measurement from warm-up.
Consolidate
Practice
Students measure 4 classroom objects using linking cubes (iterating carefully) and then using hand span. Compare results and explain the difference. Exit ticket: which gives more consistent results, your hand or a cube? Why?
Exit ticket
Students measure 4 classroom objects using linking cubes (iterating carefully) and then using hand span. Compare results and explain the difference. Exit ticket: which gives more consistent results, your hand or a cube? Why?
Gaps or overlaps in iteration. When iterating, the end of one cube must touch the start of the next. Ask both students to re-measure carefully side by side. This common error directly reinforces the need for precision.
Length is one-dimensional: line up units in a row. Area is two-dimensional: cover the entire surface. Tiling requires units in both dimensions. Show both: a row of cubes for length and a grid of cubes for area.