Stacks

What your child does

Three columns, hundreds, tens and ones, each holding blocks of its own size with the count written above. A second number arrives under the columns: blocks to add, or holes to fill by taking blocks away. Your child settles the board.

When the ones overflow, ten of them ride up a column and become one ten. When there are not enough ones, a ten comes down and bursts into ten of them. Nobody says "carry" or "borrow". Both are done, many times, before the written method appears anywhere.