There is no fixed duration; mastery depends on several factors, but we can sketch a useful approximation.
Factors involved
- Consistency of daily practice (by far the most important).
- The learner’s age and focus.
- Quality of the curriculum and gradual difficulty.
An approximate timeline
- First months: representing numbers and simple addition/subtraction.
- 3–6 months: complements (friends of 5 and 10) and compound subtraction.
- 6–12 months: multiplication, division and the beginnings of anzan.
- Over a year: fast multi-digit mental calculation.
Remember that consistency matters more than duration; 15 minutes daily beats long, infrequent sessions. Track your progress on the practice page.