Which Times Tables do Students Find Difficult?

There’s an excellent article on today’s Guardian Datablog looking at a computer based study (with 232 primary school students) on which times tables students find easiest and difficult.  Edited highlights (Guardian quotes in italics):

Which multiplication did students get wrong most often?

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The hardest multiplication was six times eight, which students got wrong 63% of the time (about two times out of three). This was closely followed by 8×6, then 11×12, 12×8 and 8×12.

The graphic shows the questions that were answered correctly the greatest percentage of times as dark blue (eg 1×12 was answered 95% correctly).  The colours then change through lighter shades of blue, then from lighter reds to darker reds.  It’s interesting to see that the difficult multiplications cluster in the middle – perhaps due to how students anchor from either 5 or 10 – so numbers away from both these anchors are more difficult.

Which times table multiplication did students take the longest time to answer?

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Maybe unsurprisingly, 1×1 got answered the quickest (but perhaps illustrating the hazards of speed, pupils got it wrong about 10% of the time), at 2.4 seconds on average – while it was 12×9 which made them think for longest, at an average of 7.9 seconds apiece.

It’s quite interesting to see that this data is somewhat different to the previous graph.  You might have expected the most difficult multiplications to also take the longest time – however it looks as though some questions, whilst not intuitive can be worked out through mental methods (eg doing 12×9 by doing 12×10 then subtracting 12.)

How did boys and girls differ?

On average, boys got 32% of answers wrong, and took 4.2 seconds to answer each question.  Girls, by contrast, got substantially fewer wrong, at 22%, but took 4.6 seconds on average to answer.

Another interesting statistic – boys were more reckless and less considered with their answers!  The element of competition (ie. having to answer against a clock) may well have encouraged this attitude.  It would be interesting to see the gender breakdown to see whether boys and girls have any differences in which multiplication they find difficult.

Which times table was the hardest?

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As you might expect, overall the 12 times table was found most difficult – closely followed by 8.   The numbers furthest away from 5 and 10 (7,8,12) are also the most difficult.  Is this down to how students are taught to calculate their tables – or because of the sequence patterns are less memorable?

This would be a really excellent investigation topic for IGCSE, IB Studies or IB SL.  It is something that would be relatively easy to collect data on in a school setting and then can provide a wealth of data to analyse.  The full data spreadsheet is also available to download on the Guardian page.

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