# Suugaku – What is Japanese math like?

The Japanese have a different writing from the western one and also several different cultural issues. Many end up wondering how mathematics works in Japan, thinking about that we are writing this article. Mathematics in Japanese 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 ideograms, only they also use western numbers. The great truth is that Japanese numbers and counts are much more logical and systematic than Western ones. We recommend that you already have knowledge of or about japanese numbers so as not to get lost in Japanese mathematics.

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## Wasan – The Mathematical Origin in Japan

Wasan was developed in Japan during the Edo period (1603-1867), the term wasan literally means Japanese calculus (算) (和). It was coined in the 1870s but is unfortunately in decline because of the influence of Western mathematics. There are not so many differences between Japanese and Western mathematics, it's just historical, but in practice the mathematics is always the same. Among the history of mathematics in Japan one of the proudest inventions is the soroban or japanese abacus. There are also 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 for solving systems of linear equations by eliminating dependent variables.

The difference between Japanese and Western mathematics is that they have not applied 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 to perform multiplications more easily. It consists of drawing sets of parallel lines that represent each digit of the first number to multiply. 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 encounters of the parallel lines: 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 in traditional multiplication, it's better to get the result by counting the numbers starting from behind. Look at one of the examples in the figure written in calculations to see how this method is simpler than the traditional one: 23 x 12 = (2×10 + 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 the ideograms. One of the few things that changes is the pronunciation in Japanese, if you know English it's easy because they use a lot of variations of English.

We use the same signs as in 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 (＝) for example: (X + Y = 50) in Japanese we would say X + Y は 50 です。And we use the word have to refer to the (. and,) of 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 English. Below is a list of their pronunciation:

 Japanese Derived from English addition / more tasu (足す) purasu (プラス) subtraction / minus hiku (引く) mainasu (マイナス) multiplication / times kakeru (掛ける) division / divided waru (割る) Fractions bun (文)

The verbs add, subtract, multiply and divide followed by zan (算) is 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 of Japanese math. For you to delve deeper, we will leave you a vocabulary table for you to carry out your research:

Portuguese Japanese Romaji
Math 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
The amount ryou
Volume 体積 taiseki
Area 面積 menseki
Angle 角度 kakudo
Length 長さ nagasa
Weight 重さ omosa
Speed 速さ hayasa
Prime number 素数 sosuu
negative number 負の数 I went in the sweat
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
Multivariate Calculus 多変数微分積分学 tahensuubibunsekibungaku
Fractions 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
trapeze 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