Gather everyone's attention. Make it clear the lesson is going to begin.
* Warm up with some brisk mental practice. Make this fun and do something different every day.
* Start with something easy everyone can join in with - counting in tens from different numbers, or chanting a times-table backwards.
* Involve the children as much as possible. Give them digit cards to hold up when answering questions.
* Get children to explain to the class how they did a calculation, either orally or by jotting on the board * Target individuals, or groups, with particular questions.
* Make group work manageable. Four groups are usually enough, with activities at three levels of difficulty. Middle groups can do the same thing.
* Give the groups a deadline for getting their work done. Focus most attention on two groups - don't flit among them. Sit and teach them for several minutes. Target the other two groups in the next lesson.
* Towards the end, round up the whole class for more questioning and sorting out misconceptions.
* End by getting children to think about one or two key facts or ideas they have learned in the lesson and what they should remember for tomorrow.
* Prepare well so you know what children are to learn, not just what they will do. Plan the questions you will ask.
* A couple of times each week, extend your lesson by giving something to do at home - perhaps a puzzle or number game to play with their families.