Video narration
How can four boxes help you keep a tricky multiplication straight? With three plates, four cookies each, you add four, four, four. Multiplication quickly adds equal groups: three times four is twelve. For twenty-three times fourteen, use the lattice method, a four-box grid. Put two and three across the top, one and four down the side. Multiply each pair: two times one, zero-two; three times one, zero-three; two times four, zero-eight; three times four, twelve. In each box, tens go in the top triangle, ones in the bottom; zeros mean no tens. Now add diagonals from bottom right. First, two. Next, one plus three plus eight is twelve: write two, carry one to the next diagonal. Then zero plus two plus zero plus the carried one is three. Last diagonal: zero. That's how: multiply each box, add diagonals, and read the answer: three hundred twenty-two.