Turning the Tables on Government Tests
Primary school pupils in the UK will soon face tests on their times tables up to 12×12 before starting secondary school. Read the story here.
This may seem daunting to youngsters and some adults struggle to remember seven eights are fifty-six when put on the spot. At first sight it looks like they need to remember 144 distinct pieces of information. However, this can be massively reduced. Multiplication is commutative (which means a x b = b x a) so you only have to remember half the tables. If you know 6 x 7 you also know 7 x 6. We’ve reduced the workload to 72 pieces of data. Take out the one, two, ten, five and eleven times tables as these all have simple patterns and it starts to look far less scary. The nine times table is easy if you know that the digits always add up to nine. (eg. 9×5 = 45 and 4+5=9, 9×8=72 and 7+2=9, etc.) You can use this property to work out multiples of nine on your fingers. The remaining tables can be learned with simple mnemonics. Of course, as the test is against the clock students need to practise to speed up but, without time pressure, kids can learn their tables in an afternoon. No need to return to the old-fashioned chanting in class, “one two is two, two tows are four”. 😉