Children with dyscalculia do not struggle with mathematics in only one way. Instead, their difficulties usually fall into four major categories that affect how they understand and work with numbers. Listen to what three parents have to say:
Understanding these categories helps parents and teachers identify where the real problem lies and choose the right intervention.
The four main deficit areas are:
- Counting and multiplication facts
- Mental math
- Place value
- Procedural math
These four areas form the foundation of mathematical learning. They build on one another, and when weaknesses exist at the foundation, difficulties spread upward into more advanced mathematics.
1. Counting and multiplication fact difficulties
Many students with dyscalculia struggle with the most basic number sequences.
Common signs include:
• Needing to count from 1 every time.
For example, when asked, “What is 8 + 6?”, a student might count: 1, 2, 3, 4, 5, 6, 7, 8… and then continue counting for another six numbers. In other words, they count all instead of counting on.
• Difficulty counting backwards.
Counting forward is foundational to addition, and counting backward is foundational to subtraction.
• Struggling to skip count (even in 2s).
Skip counting is foundational to multiplication. Some students may memorize parts of their multiplication tables, but if they cannot skip count reliably, they lack a deeper understanding of how multiplication works.
• Trouble learning multiplication tables.
Multiplication tables are essentially structured skip-counting patterns. For example: 3, 6, 9, 12. This sequence represents the 3-times table. Without strong counting sequences, multiplication tables become extremely difficult because the student cannot recognize or generate these patterns.
2. Mental math difficulties
Mental math requires the ability to hold numbers in working memory and manipulate them mentally.
Students with dyscalculia often struggle to perform even simple calculations in their heads.
Common signs include:
• Difficulty adding or subtracting small numbers mentally
• Losing track halfway through a calculation
• Needing to write down very simple problems
• Forgetting intermediate numbers during calculations
For example: 47 + 6
Most students automatically think:
47 + 3 = 50
50 + 3 = 53
A student with dyscalculia may instead count slowly on their fingers, restart multiple times, or lose track of the count.
Mental math difficulties are strongly related to weaknesses in:
• Working memory
• Sequential processing
• Number sense
Working memory is the ability to hold information in the mind for a short time while using it. In mathematics, it allows a student to remember intermediate numbers while solving a problem. For example, when calculating 47 + 6 mentally, the learner must hold 47 in mind, add 3 to reach 50, and then add the remaining 3.
Sequential processing is the ability to understand, remember, and produce information in the correct order. Mathematics relies heavily on sequences, such as counting numbers in order, following the steps of long division, or remembering multiplication tables. When sequential processing is weak, students may lose their place, skip steps, or mix up the order of operations.
Number sense refers to an intuitive understanding of numbers and their relationships. It includes recognizing quantities, understanding that numbers can be broken apart and recombined, estimating the size of numbers, and seeing patterns in calculations. Students with good number sense understand that 8 + 6 can be thought of as 8 + 2 + 4, while learners with poor number sense may need to count every number one by one.
3. Place value difficulties
Place value is one of the most critical concepts in mathematics, and it is a major difficulty for many students with dyscalculia. They may struggle to understand that 345 means 3 hundreds, 4 tens, and 5 ones. Instead, they may see it as simply three separate digits rather than parts of a structured number system.
Common signs include:
• Writing numbers incorrectly
• Confusing tens and ones
• Difficulty understanding large numbers
• Misaligning digits in column calculations
• Struggling with regrouping (carrying and borrowing)
For example, a student might think 402 is smaller than 39 because 4 is smaller than 9. This shows that the learner is focusing on individual digits rather than understanding the value each digit represents.
In practice, this difficulty often shows up in how numbers are written. For example, a learner may write:
• 7,532 as 7000532
• 7,053 as 7,53
These errors show that the learner does not fully understand how digits represent hundreds, tens, and ones, or how zeros function as placeholders in the base-ten system.
Without a clear mental model of the base-ten system, higher mathematics becomes extremely difficult.
4. Procedural math difficulties
Procedural math refers to written algorithms and multi-step calculations. These include column addition with carrying, subtraction with borrowing, long multiplication, long division, fraction procedures, decimals, percentages, order of operations, and integers.
Students with dyscalculia often:
• Forget steps in procedures
• Mix up operations
• Lose their place in the calculation
• Make errors even when they understand the concept
For example, even if they learned the procedure the day before, during long division, they may forget to:
- Divide
- Multiply
- Subtract
- Bring down
This happens because procedural math requires strong:
• Attention to detail
• Sequential processing
• Working memory
• Long-term memory
Long-term memory is the ability to store information in the brain for extended periods of time and retrieve it when needed. In mathematics, it allows learners to remember previously learned facts, rules, and procedures, such as multiplication tables, number relationships, and the steps used in written calculations. When long-term memory is weak, students may need to relearn the same mathematical facts or procedures repeatedly because the information does not become firmly stored.
When these skills are weak, procedures are easily disrupted.
Why these four areas matter
Mathematics is hierarchical. Skills build on one another.
For example:
• Weak counting skills affect multiplication.
• Weak place value understanding affects addition, subtraction, and decimals.
• Weak mental math slows all calculations.
• Weak procedural skills make written mathematics unreliable.
Because mathematics is cumulative, gaps in its foundations tend to grow larger over time if left unaddressed. Weakness in any of these four areas can later also affect more advanced topics such as algebra, geometry, transformations, and statistics.
The good news
The encouraging news is that these skills can improve with the right training.
Effective intervention needs to strengthen the cognitive foundations of mathematics, such as working memory, sequencing, and attention. However, cognitive training alone is not enough. Students must also be explicitly and systematically taught the academic side of mathematics.
Mathematical knowledge must be applied and practiced through carefully structured instruction that follows sound learning principles. Concepts should be introduced in small, logical steps, practiced until they become reliable, and continuously connected to previously learned material.
When cognitive skills and academic instruction are developed together, students often experience significant gains in both mathematical confidence and performance.
Edublox offers cognitive training and live online tutoring to students with dyscalculia and other learning challenges. We support families in the United States, Canada, Australia, and beyond. Book a free consultation to discuss your child’s learning needs and learn more below:
- The 4 Core Math Skill Deficits in Dyscalculia was authored by Sue du Plessis (B.A. Hons Psychology; B.D.), a dyscalculia specialist with 30+ years of experience in learning disabilities.
- Edublox is proud to be a member of the Institute for the Advancement of Cognitive Education (IACE), an organization dedicated to improving learning through cognitive education and mediated learning approaches.
