It is estimated that dyscalculia affects between 3-6 % of the World population.
Dyslexia has become "quite" well known in recent years (although the majority of the population think it's just a problem with reading and spelling), but many people haven't even heard of dyscalculia.
Dyscalculia causes people to have difficulties with maths and numbers, in spite being of normal intelligence. This can be anything from difficulty distinguishing between + & - to having to use your fingers to add up 3 + 8 for instance.
It can be very confidence sapping and can lead to children and adults thinking they are stupid and useless.
It can cause particular problems in adulthood; especially when choosing a career. If you try to think of a job that doesn't involve calculating simple maths in your head, there aren't many.
It doesn't only cause problems in working life, dyscalculia effects people in there every day life.
It causes an inability to work out change in a shop, tell the time or even find your way around.