Dyscalculia and Low Numeracy

Dyscalculia is difficulty in learning or understanding arithmetic. Low numeracy is the inability to work with, understand, and apply numerical concepts.

Dyscalculia is estimated to affect 3-6% of the population, although it’s estimated that many people with the condition are undiagnosed, because it’s not as well-known as dyslexia.

Low numeracy or innumeracy can influence healthy behaviors, financial literacy, and career decisions. These influences can negatively affect economic choices, financial outcomes, health outcomes, and life satisfaction. While dyscalculia can be identified not only through symptoms but also through fMRI brain scans, the causes of low numeracy are more complex, and may be related to low socioeconomic status, the mother’s level of numeracy, age, gender, and country. Low numeracy affects half of people of working age in the United Kingdom.

Design considerations

When we design for people with dyscalculia and low numeracy, we need to:

  • Round numbers to the nearest whole number whenever possible.
  • Leave space around numbers.
  • Fill in information that we already have, so the user doesn’t have to provide it.
  • Use sentences to add context about numbers.
  • Let people include spaces when entering numbers.
  • Do user research with people who struggle with numbers.

We need to avoid:

  • Using decimals unless it’s money.
  • Overwhelming people with too much content.
  • Expecting readers to repeat or remember numbers.
  • Using tables and grids without explaining what the numbers mean.
  • Rush users to enter a number accurately.
  • Forcing people to enter a number or do math to verify themselves.

Often, making small changes after usability research can result in high changes to understanding for our audiences. Including people who struggle with numbers, both inside and outside the team, helps us better understand what the challenges are.

Additional resources