Here is a subtraction from the shop: a stall had 342 apples and sold 158 of them. Look at the units column for a moment. Can you take 8 apples away from 2 apples?

Hands up: what could we do when the top number in a column is too small to take away from?

We work four subtractions on screen, one at a time. Watch the crossed-out borrow-note in each column and follow where the ten travels. Get ready to predict which columns will need renaming.

Now we work these three subtractions together on the board. Start each one by writing the borrow-note where a column is too small, then read down the answer row column by column.

• 365 − 142 — no renaming, to warm up.
• 451 − 268 — rename in the units and the tens.
• 305 − 178 — rename across the zero in the tens.

Before each column, say out loud whether we can take away straight off, or whether we need to rename first.

Now we solve these shop and school problems together on the board, each one a step harder. One pupil works each problem while the rest of the class follows on the board and gets ready to agree or correct.

First, 268 people leave a crowd of 345 at a match. Next, a shop with 524 items sells 287. Then a library of 403 books lends 176 — watch the zero in the tens. Last, a hall of 600 seats has 354 taken — two zeros, so the borrow has to travel the whole way across. Read each story, decide it is a take-away, then work the columns from the right.