how many 'f's?

This puzzle has been fooling people for decades. You can use it to demonstrate how our mind sometimes plays tricks on what we believe. The puzzle can also be used to support themes of concentration, accuracy, assumptions, and creative or lateral thinking (which can be employed to devise an alternative method of arriving at the right answer; for example using the 'find' feature in your computer program). The layout is probably important in the way that it works. Show the box below to people and ask them to read the words and count the number of times the letter f (or F) appears. Most people get it wrong. Try it yourself, and then check your answer carefully. It's not a trick question - the trick is the way that the mind works in identifying letters.

How many 'f's?

FINE POINT

.It is easy to miss the finer points in life. Folk are frequently guilty of falling into this trap.

The letter f appears eight times in the box. People commonly count seven, by failing to see the last but one f.