This is an intermediate step in the progress towards developing an efficient, standard method of multiplication on paper. It presumes a good knowledge of times tables before starting.
An important part of this process which is often neglected, is that an estimate of the answer should be quickly worked out ‘in your head’ before beginning the written answer. This can be done by quickly rounding the numbers.
For example: 637 x4 is round about 2400.
This intermediate process does the sum 637 x 4 in four parts:
1. Multiply the hundreds 600 x 4
2.Multiply the tens 30 x 4
3. Multiply the units 7 x 4
4. Add the 3 answers.
The first three stages can be reversed, multiplying the units first.