# Suugaku - How is Japanese mathematics?

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The Japanese have a different writing from the western one and also diverse cultural issues. Many end up doubting how mathematics works in Japan, thinking about it we are writing this article. Japanese mathematics is called Suugaku (数学) and there are two of them in Japanese, the western one is called yousan (洋算) and the Japanese way of wasan (和算).

Japanese also has its own numbers using the ideograms, only they also use western numbers. The big truth is that Japanese numbers and counts are much more logical and systematic than Western ones. We recommend that you already have knowledge or about japanese numbers so as not to get lost in Japanese mathematics.

## Wasan - The mathematical origin in Japan

Wasan was developed in Japan during the Edo period (1603-1867), the term wasan literally means Japanese (算) calculus (和). It was coined in the 1870s but is unfortunately declining because of the influence of Western mathematics. There are not so many differences between Japanese or Western mathematics, it is just historical, but in practice mathematics is always the same. Among the history of mathematics in Japan one of the most proud inventions is the soroban or Japanese abacus. There is also the Sangaku which are mathematical puzzles that were placed in temples and shrines to challenge people. Seki Kowa was the most influential Japanese mathematician before contact with the West. He discovered solutions to solve systems of linear equations, eliminating dependent variables.

The difference between Japanese and Western mathematics is that they did not apply much of their research and discoveries to areas other than geometry. So they ended up adopting Western mathematics.

#### Multiplication trick

The Japanese have a method for making multiplications more easily. It consists of drawing sets of parallel lines that represent each digit of the first number to be multiplied. And then draw sets of parallels, perpendicular to the first sets of parallels, corresponding to each digit of the second number (the multiplier). Look at the figure and count the number of parallel line encounters: I can't explain it well in words, but each alignment of the parallel lines represents a digit of the final result. And just like traditional multiplication, it is better to get the result by counting the numbers starting from the back. See one of the examples in the figure written in calculations to see how this method is simpler than the traditional one: 23 x 12 = (2x10 + 3) (1 × 10 + 2) = 2x1x102 + [2x2x10 + 3x1x10] + 3x2 = 276

## How do the Japanese do calculations?

Mathematics in Japan is done in the same way as in the west. Even Japanese children are already introduced to the Arabic numbers we use, but they also use ideograms. One of the few things that changes is the pronunciation in Japanese, if you know English it is easy that they use enough variations of English.

We use the same signs as Western mathematics in Japanese. However, Japanese also uses the verbs to add, multiply ... along with Japanese ideograms. We use the tasu (足す) as an addition verb, to add or more. Example: 7 + 3 = 10 / nana tasu san wa juu desu (七足す三は十です). In Japanese we use the desu (です) to speak the equal (＝) such as: (X + Y = 50) in Japanese we would speak X + Y は 50 です。And we use the word ten to refer to the (. and,) of the decimal numbers. Example: 3,5 (san ten go). In Japanese, we can also use the English variation of the 4 mathematical operations (kangenjojo - 加減乗除). They are the same as in Portuguese. Below we will see a list of their pronunciation:

 Japanese Derived from English Addition / more tasu (足す) purasu (プラス) Minus / minus hiku (引く) mainasu (マイナス) Multiplication / times kakeru (掛ける) Split / split waru (割る) Fractions to 11/13 bun (文)

The verbs to add, subtract, multiply and divide followed by zan (算) are used to say addition, subtraction, division, etc.引き算 (hikizan), 掛け算 (kakezan), 割り算 (warizan),

## Japanese math vocabulary

Of course, this is just the basics about math in Japanese. For you to go even deeper, we will leave a vocabulary table for you to carry out your research:

Portuguese Japanese Romaji
Mathematics 数学 suugaku
Number 数字 / 数 suuji / kazu
Digit keta
Decimal 小数 shousuu
Fraction 分数 bunsuu
Divider 約数 yakusuu
Exponent 指数 shisuu
Even number 偶数 guusuu
Odd number 奇数 kisuu
Irrational number 無理数 murisuu
Rational number 有理数 yuurisuu
Reason Hi
Amount ryou
Volume 体積 taiseki
Area 面積 menseki
Angle 角度 kakudo
Length 長さ nagasa
Weight 重さ omosa
velocity 速さ hayasa
Prime number 素数 sosuu
Negative number 負の数 fu no suu
Positive number 正の数 I don't know
Calculation 微積分学 bisekibungaku
Differential calculation 微分学 bibungaku
Integral Calculus 積分学 sekibungaku
Multivariable calculation 多変数微分積分学 tahensuubibunsekibungaku
Fractions to 11/13 分数 bunsuu
Trigonometry 三角法 sankakuhou
Probability 確率 kakuritsu
Statistics 統計 toukei
Geometry 幾何学 kikagaku
Algebra 代数学 daisugaku
Linear algebra 線型代数学 senkeidaisuugaku
Differential Geometry 微分幾何学 binbukikagaku
Square 正方形 seihoukei
Triangle 三角形 sankakukei
Rectangle 長方形 chouhoukei
Trapezoid 台形 daikei
Parallelogram 平行四辺形 heikoushihenkei
Diamond 菱形 hishigata
Kite 凧形 takogata
Cube 立方体 rippoutai
Pyramid 角錐 kakusei
Square pyramid 四角錐 shikakusei
Prism 角柱 kakuchuu
Triangular prism 三角柱 sankakuchuu