EUCALCULIA 2.3

See a quantity displayed visually → type the number. This is the core exercise for building instant number recognition. The stimulus flashes briefly, then disappears. Try to recognize without counting.

See a digit (e.g., "7") → select the matching visual quantity from 3 options. Strengthens the bidirectional connection between number symbols and their magnitudes.

See a partially filled frame → type how many more are needed to complete 10 (or 20). Builds automatic knowledge of number complements, essential for mental arithmetic.

Based on Relational Frame Theory. See two quantities side by side. After they disappear, a question appears: "Same parity?", "Left > Right?", "Sum > 10?", etc.

The question is hidden until after the stimuli vanish to force you to encode both quantities in working memory before comparing.

Paced Auditory Serial Addition Test (visual version). See quantities one after another → add the current one to the previous one. Trains working memory and arithmetic simultaneously.

See two quantities with + or − between them → compute the result. Builds automatic retrieval of arithmetic facts rather than calculating from scratch.

A continuous stream of numbers. After each one, recall what appeared N steps ago:

• 1-back: What was the previous number?
• 2-back: What was 2 numbers ago?
• 3-back: What was 3 numbers ago?

The "N" varies randomly within your level, training flexible working memory updating. This is one of the few exercises shown to improve fluid intelligence.

A 5×2 or 5×4 grid where filled squares represent the quantity. Based on the classic "ten-frame" used in education. Great for seeing numbers as parts of 10 or 20.

Standard dice pip patterns (1-6) or domino halves. Very familiar arrangements that support instant recognition through pattern matching.

Classic tally marks in groups of 5 (four vertical + one diagonal). Useful for understanding grouping and the structure of numbers.

Hand representations showing raised fingers. The most intuitive and embodied number representation. One hand for 1-5, two hands for 6-10.

Simplified abacus with two rods. Top rod (red beads): each bead = 5. Bottom rod (green beads): each bead = 1. Example: 7 = one red + two green.

Playing card pip layouts (hearts). Familiar patterns from card games, supporting pattern-based recognition up to 10.

3D isometric cubes arranged in a grid. Engages spatial reasoning and requires counting objects that have depth and perspective.

Coins of three types with different values: Copper = 1, Silver = 2, Gold = 5. You must add up the total value. Mirrors real currency systems (1, 2, 5 cent coins) for direct real-world transfer.

Numbers shown as Roman numerals (I, II, III, IV, V, etc.). While not a pure quantity representation, these are common in real life (clocks, chapters, dates).

Clock face with hour hand pointing to the number (1-12). Connects number sense to time-telling, another essential daily skill.

Squares arranged in a rectangular pattern showing factors (e.g., 6 shown as 2×3). Builds intuition for multiplication and area.