Numeracy issues can occur due to a range of difficulties, the most severe being the inability to read or understand numbers. However, the main problems tend to revolve around decoding. When reading measurement an individual with cognitive impairment may understand the concept of 90cms as a length but find it hard to cope with the fact that 0.9m and 900mm are the same length. Individual difficulties include:
Tasks that involve recalling significant amounts of numbers or application including lengthy techniques may be difficult. Examples include, remembering phone and pin numbers, working through an online process such as booking and paying for a train ticket. Shopping online with multiple offers and alternatives.
This involves working memory where individuals may misread and mistype numbers as well as have copying issues. Where numbers look or sound similar these may cause confusion for example, 7 and 9 or 66 and 56 – may be based upon the language and where numbers are read out with no visual cue or may be written with no audio support.
An alternative presentation of numbers may cause problems, so the difference between the calculator keypad, the numbers on a keyboard and a phone pad may result in incorrect numbers being used to unlock or access product services. Cognitive load associated with decoding numbers and symbols should be considered when offering alternative strategies. These alternatives could further exacerbate executive functioning difficulties, for example saying ‘1/5’ as ‘open fraction one over 5 close fraction’ compared to saying ‘one fifth’ – this is to do with the amount said or verbosity.
If there is an impairment of abstract thinking and reasoning, problem solving and working online with numbers in any way will be impacted upon to such an extent that users will be unable to access arithmetical content, use numerical passwords or cope with decision making based on numerical information such as entering vehicle registration numbers where L and O many be confused with 1 and 0 (one and zero), particularly when using lower case.
Items that need to be added to an edit form in a particular manner such as zip codes or postal codes, dates, time, birthdates etc. may also cause confusion.
Attention limitations may cause problems with completing items accurately where there are a required number of steps or where midway between two processes concentration has been lost due to another distraction e.g. adverts, pop-up, interstitials etc. This issue is linked to memory difficulties and being unable to cope with versioning – noticing the different file names where numbers have been used and not a complete change of title.
Receptive and expressive speech and language impairments may hamper the ability to cope with numbers provided auditorily such audio CAPTCHA. Cultural differences in the way numbers and math are spoken may cause issues around the order of presentation and the words used such as parentheses (US) or brackets (UK).
The inclusion or exclusion of certain elements of an equation when read aloud can have an impact on understanding, for example, leaving out parentheses or brackets.
Different voices used by text to speech engines read numbers in different ways for, example, phone numbers may be read incorrectly.
This includes, difficulties with reading the symbols representing numbers and numerical concepts which can cause confusion, increased time taken when completing forms and the misreading of sums. This could be considered as a decoding issue. An example would be ‘50%’ failing to be understood as ‘fifty percent’.
There are several perceptual difficulties that may impact on numerical ability such sequential processing where comprehension of multiple numerical items in a process may be impacted upon such as addition and subtraction where the order of numbers is crucial. Sequencing difficulties also impact on time and the duration of time or even size of numbers. Auditory perceptual difficulties occur where numbers may appear to be misheard but actually hearing can be good and it is the comprehension that is affected so the number or numerical concept does mean anything. For example the audio CAPTCHA is read out aloud but in the time given the user is unable to process the content.
Visual perceptual difficulties may include spatial and pattern recognition where the user may have problems with diagrammatic representations of numerical and symbolic information. For example extracting information from a graph or diagram, comparing diagrammatic information or where position impacts on the concept – ¾ compared to 4/3.
Reduced knowledge may occur where an individual has sustained a brain injury and prior understanding of numbers and numerical concepts have been lost. This may result in all the aforementioned issues occurring.
The abstract nature of numerical information may be impacted on by a lack of understanding the presentation of problems that are inappropriate to the concept of the user’s environment and lifestyle – this may include items such as examples that are given as comparisons such as weighing as much as an elephant – the user is not talking about elephants but making a comparison between heavy and light.
Notes on proposed solutions: