Otona Ni Yakudatsu Sansu (Bunko SP K 131-1)

[Machine Translation] Arithmetic is the art of drawing equations and diagrams and working out the answers one by one without using equations. The arithmetical thinking, which involves thinking ahead and sequencing things, is easier to apply to daily life and work than mathematics, and can be enjoyed by adults only. From the nostalgic Tsurukame math, to problems involving figures that require inspiration, to abstract problems involving speed, proportion, concentration, averages, ratios, and so on. At the level of entrance examinations for difficult junior high schools, it is also important to subtract if you can't push. This is an introduction to arithmetic for adults that will loosen your stiffened brain.

方程式をあえて使わず、計算式や図をかいて、ひとつひとつ手を動かして答えを導く算数。先を読み、順序だてて物事を考える算数的発想は、数学よりも日常生活や仕事に応用しやすく、大人だからこそ楽しめる。懐かしいつるかめ算から、ひらめきが必要な図形問題、そして速さ、割合、濃度、平均、比など抽象的な文章題へ。難関中学入試レベルでは、押してだめなら引くのも大事。固くなった頭をときほぐす、大人のための算数再入門。