Our #Education21 campaign highlights how educational research has helped us to better understand the needs of young people with Down syndrome and how it is improving outcomes for many thousands of children today. Find out more...

#9. Learning about numbers is difficult

Most young people with Down syndrome find learning about numbers difficult and only a few acquire the number skills sufficient for everyday life. Research has begun to explore possible reasons for these difficulties but more studies are needed to better inform more effective teaching approaches.

What educational research has shown

Educational research suggests that most children and adults with Down syndrome (but not all) find it difficult to learn about and use the number system.[1 - 4]

A 1999 study of teenagers attending mainstream schools in the UK reported that 94% could count objects to 20 and do simple addition with numbers within this range. Half of this group could recite the numbers to 50 and a third could count more than 20 objects accurately and recite numbers accurately to 100. While all the teenagers could add small numbers, 78% could complete simple subtraction, 28% could complete simple multiplication and 17% could complete simple division.[3] These findings and similar data from other countries suggest that most young people with Down syndrome do not acquire a sufficient understanding of the number system for use in everyday activities - limiting their daily lives and work opportunities.

While several surveys report these limited achievements, few studies explore why most children with Down syndrome find number so difficult. This research has generally focused on the first stages of learning to count. Research suggests that during the early stages of learning to count and to understand cardinality (that the last count word tells you how many you have), children with Down syndrome progress at the rate expected for their mental age.[5] There is also some evidence that their progress with number is linked with their progress with language - as is also the case for typically developing children.[1, 6]

Working memory is known to influence number learning for typically-developing children and may also be a limiting factor as it is known to be impaired in children with Down syndrome. A number of studies report that the children's number progress typically lags behind their reading progress.[1]

Evidence indicating that children with Down syndrome have relative strengths processing visual information has led researchers to begin to explore the use of teaching systems that make full use of visual imagery to accurately represent the number system.[7]

How this is helping

Educators are aware that it is important to give extra focus to teaching number and the language for number.

Teaching systems which make full use of materials that accurately represent the number system are being used to help illustrate number concepts and also to support working memory.

Unanswered questions

Future research is needed to understand:


  1. Brigstock, Hulme, Nye (2008) Number and arithmetic skills in children with Down syndrome. Down Syndrome Research and Practice. https://library.down-syndrome.org/reviews/2070/
  2. Faragher, R. & Clarke, B. (2014) Mathematics profile of the learner with Down syndrome. Chapter in R. Faragher and B. Clarke (Eds.), Educating Learners with Down Syndrome. ( pp 119-145) Routledge Education.
  3. Buckley SJ, Bird G, Sacks B, Archer T. The achievements of teenagers with Down syndrome. Down Syndrome News and Update. 2002;2(3);90-96 https://library.down-syndrome.org/updates/178/
  4. Monari Martinez E. Learning mathematics at school....and later on. Down Syndrome News and Update. 2002;2(1);19-23. https://library.down-syndrome.org/practice/160/
  5. Nye J, Clibbens J, Bird G. Numerical ability, general ability and language in children with Down syndrome. Down Syndrome Research and Practice. 1995;3(3);92-102. https://library.down-syndrome.org/reports/55/
  6. Nye J, Fluck M, Buckley SJ. Counting and cardinal understanding in children with Down syndrome and typically developing children. Down Syndrome Research and Practice. 2001;7(2);68-78. https://library.down-syndrome.org/reports/116/
  7. Nye J, Buckley SJ, Bird G. Evaluating the Numicon system as a tool for teaching number skills to children with Down syndrome. Down Syndrome News and Update. 2005;5(1);2-13. https://library.down-syndrome.org/updates/352/