The 0Maths blog

Relative answering times

The purpose of this graph is to help teachers see (through a glass, darkly) the mental arithmetic techniques a student may be using. For example:

• A grey (silver) circle means an answer took more than 6 seconds which indicates that the result probably did not come from long term memory. They need more practice.
• A gold circle means an answer took less than 6 seconds which indicates it likely came from long term memory.
• If times are smaller when closer to the 5 or 10 lines, the student is using an appropriate strategy to calculate each answer.
• Consistently bigger than average circles along the 9 lines (and about the same size as one another, even 2×9 and 5×9) mean a student is sticking to the 9 times table finger trick instead of trusting their memory.
• Times not roughly symmetrical about x=y mean a student is not using commutativity.
• Times increasing proportionately to the numbers in the question mean answers are likely coming from counting on.

Use with caution: any inferences are only as reliable as the data they are based on. Many other factors can influence answering times (distractions, energy levels, etc).