Each full side is equal · complete text alternative
Role
Adult ordinary model; exposed solution separate from genuine blank own work
Complete source
Day 58 ordinary 245+□=390+75.
Full alternative
An adult equality model for 245+□=390+75. The known right side is 465. The missing left part is 220 because 465−245=220. Substitution gives 245+220=465 and 390+75=465. Schematic bars stand for equal whole amounts and are explicitly not to scale; the box value 220 is not the whole-side value 465.
Rights
Original planned geometry and prose ©NeuroForgeIO Pty Ltd 2026, CC BY 4.0; curriculum/source text stays under its own notices. No banknote designs, logos, cultural motif or pupil-image copying.
Status
Original SVG and PNG constructed in this source candidate. Preserved brief predates construction; different whole source/art and Root Browser acceptance remain pending.