### Bat and ball

A bat and a ball together cost $1.10

The bat costs one dollar more than the ball

how much does the ball cost?

The vast majority of people say 10 cents. The answer is 5 cents. Our intuition tells us that the ball costs 10 cents.

Why does this error occur? Mode 2 is lazy and the Fast Mode kicks in automatically with the incorrect answer – you need algebra to get the correct answer – the slow mode needs to be engaged with visual thinking:

?+(100+ ?)=110

2 ?+100=110

2 ?=10

?=10÷2

?=5