A growing body of research has shown that children with mathematics difficulties (MD) encounter problems in a range of mathematical tasks including mathematical computations, mathematical concepts and word problems. However, limited work has been accomplished to date that documented the children’s specific difficulties or problems in each category of mathematical tasks. The present study examined whether or not children with MD face more difficulties with some operations in each category than other operations. The study selected 13 grade six children with MD from two primary schools in Addis Ababa, Ethiopia. Examination of the students’ performance on a 50-item curriculum-based mathematics test showed that (i) on the computation subtest, the children performed significantly poorly on items with multiplication, division and mixed operations as compared to computation items that require addition and subtraction; (ii) on mathematical concepts, the children performed significantly worse on all items but they performed slightly better on principles and rules; and (iii) on word problems, the children performed significantly poorly on all five types of items (addition, subtraction, multiplication, division and mixed operations). Overall, the findings show that children with MD face difficulties with several types of mathematical (computation, concepts and word problem) tasks except computation items that require the application of addition and subtraction.