Place Value.
Make the grouping of ones, tens, hundreds, and smaller units visible.
Place value depends on groups of ten and on the value assigned to each position. A written digit can look unchanged while its contribution changes: the 4 in 42 represents four tens, while the 4 in 24 represents four ones.
Base-ten blocks provide fixed groups, and linking cubes let learners assemble those groups. Move between a model, a spoken description, and a written number. Each representation should refer to the same quantity.
Allow nonstandard representations, such as two tens and fourteen ones for 34. Exchanging pieces without changing value gives regrouping a meaning beyond a written procedure. State the unit explicitly before reusing the same blocks for decimals.
