Step 3 Objective

Extend efficient written methods to long multiplication of TU by TU.

Examples of what pupils should know and be able to do

As above, use the grid method and partitioning before using the standard method for long multiplication.

Probing questions

Give pupils a multiplication question (for example, 37 × 14) calculated by both the grid method and long multiplication. Ask questions such as:

What two numbers multiplied together have the answer 370?

How would it be different if I worked out 14 × 37, i.e. put the numbers the other way around?

Give pupils some long multiplications with mistakes in them.

Ask them to identify the mistakes, talk through what is wrong and say how they should be corrected. Ask them to estimate the answers.

What if pupils find this a barrier?

TL4Y7 Number 2 N2.1 - Acrobat pdf document (76Kb) is useful.

Multiplication Grid ITP - Zip file (458Kb) can be used for TU × TU and is very useful for whole-class work on using and discussing the grid method.

For guidance on written multiplication refer to the document 'The National Numeracy Strategy: Teaching written calculations – guidance for teachers at key stages 1 and 2' (QCA/99/486) pages 49-55.