Words Related to Numbers -DAILY NIHONGO-

【+(たす)】”TASU”

Meaning: 

plus

Usage: 

「1+2=3」
(いち たす に は さん)
(Ichi tasu ni wa san)

  • “+” is called 「足す (たす / tasu)」 in Japanese, but sometimes it is called 「プラス (ぷらす / purasu)」 too. 「足す」 is used when reading out calculation formulas, and 「プラス」 is often used in other cases:
    • 「今月の売り上げは先月と比較して+30%だった。」
      (こんげつのうりあげはせんげつとひかくして ぷらす さんじゅっぱーせんとだった。)
      (Kongetsu no uriage wa sengetsu to hikaku shite purasu sanjuppāsento datta.)
      “This month’s sales were +30% compared to those of last month.”
  • Calculations that use + (addition) are called 「足し算 (たしざん / tashizan)」.
    • 「あの子が2年前に15歳だったってことは、今は17歳。簡単な足し算じゃん。」
      (あのこがにねんまえにじゅうごさいだったってことは、いまはじゅうななさい。かんたんなたしざんじゃん。)
      (Ano ko ga ni nen-mae ni jūgo sai datta ttekotowa, ima wa jūnana sai. Kantan-na tashizan jan.)
      “If she was 15 two years ago, then she is 17 now. It’s a simple addition.”
  • 「プラス (ぷらす / purasu)」 means positive and optimistic in Japanese. When you say「彼はプラス思考だ (かれはプラスしこうだ / Kare wa purasu shikō da)」, you’re saying that person is a positive thinker. This refers to a person who tends to see even bad things in a positive light.
    On the other hand, 「マイナス (まいなす / mainasu)」 means negative and pessimistic. This is also used in the same way as 「プラス思考 (ぷらすしこう / purasu shikō)」, 「マイナス思考 (まいなすしこう / mainasu  shikō) for “negative thinker” .

【ー(ひく)】”HIKU”

Meaning:

minus

Usage:

「7-6=1」
(なな ひく ろく は いち)
(Nana hiku roku wa ichi)

  • Just like “plus” case, “-” is called 「引く (ひく / hiku)」 in Japanese, but sometimes it is called 「マイナス (まいなす / mainasu)」 too. 「引く」 is used when reading out calculation formulas, and 「マイナス」 is often used in other cases:
    • 「北海道では、冬に-10度以下になることも珍しくない。」
      (ほっかいどうでは、ふゆに まいなすじゅうどいかになることもめずらしくない。)
      (Hokkaidō dewa, fuyu ni mainasu jū do ika ni narukoto mo mezurashiku-nai.)
      “In Hokkaido, it is not rare for the temperature to drop below -10°C in winter.”
  • Calculations that use – (subtraction) are called 「引き算 (ひきざん / hikizan)」.

【×(かける)】”KAKERU”

Meaning:

times

Usage:

「5×2=10」
(ご かける に は じゅう)
(Go kakeru ni wa jū)

  • Multiplying by 2 is expressed as 「2倍 (にばい / ni-bai)」, multiplying by 3 as 「3倍 (さんばい / san-bai)」, and multiplying by 4 as 「4倍 (よんばい / yon-bai)」. Multiplying by 2, in particular, is simply referred to as 「倍 (ばい / bai)」.
    • 「ゆきさんは私の倍の年齢だけど、私たちは良い友達です。」
      (ゆきさんはわたしのばいのねんれいだけど、わたしたちはいいともだちです。)
      (Yuki-san wa watashi no bai no nen-rei dakedo, watashi-tachi wa ii tomodachi desu.)
      “Yuki is twice my age, but we are good friends.”
    • 「転職して、彼女の年収は3倍になった。」
      (てんしょくして、かのじょのねんしゅうはさんばいになった。)
      (Ten-shoku shite, kanojo no nenshū wa san-bai ni natta.)
      “She changed jobs and her income tripled.”

【÷(わる)】”WARU”

Meaning:

divide

Usage:

「8÷2=4」
(はち わる に は よん)
(Hachi waru ni wa yon)

  • There are two words,「割り切れる (わりきれる / warikireru / “divisible”)」 and 「割り切れない (わりきれない / warikire-nai / “indivisible”)」, derived from 「割る (わる / waru / divide)」, which are used in division: 「割り切れる (わりきれる / warikireru)」 means that you are satisfied with a certain thing and feel good about it, and「割り切れない (わりきれない / warikire-nai)」means that you are not satisfied with a certain thing and feel bothered by it.

【=(は)】”WA / IKŌRU”

Meaning:

equal

Usage:

「3+4×5=23」
(さん たす よん かける ご は にじゅうさん)
(San tasu yon kakeru go wa nijūsan)

  • When you learn math in elementary school, you learn how to read “=” as 「は (わ/wa)」 in Japanese, but when you grow up, there are people who both say 「は (わ/wa)」 and 「イコール (いこーる / ikōru)」when reading out a formula. Both are natural. People also use 「イコール (いこーる / ikōru)」 to mean “same”. In that case, you can’t use 「は (わ/wa)」. It is only used in formulas.
    Example: X=2, X+Y=3
    「X=2。このXと足し算のXはイコールだから、Y1だね。」
    (えっくすは(いこーる)に。このえっくすとたしざんのえっくすはいこーるだから、わいは(いこーる)いちだね。)
    (Ekkusu wa (ikōru) ni. Kono ekkusu to tashizan no ekkusu wa ikōru dakara, wai wa (ikōru) ichi dane.)
    “X=2. This X and the X in addition are equal, so Y=1.”
    * “=” can be pronounced as 「は (wa)」 or 「イコール (ikōru)」, but the「イコール (ikōru)」in the middle cannot be replaced by 「は (wa)」.

【式(しき)】”SHIKI”

Meaning:

formula

Usage:

「解答用紙には式も書いてください。」
(かいとうようしにはしきもかいてください。)
(Kaitō-yōshi ni wa shiki mo kaite-kudasai.)
“Please write formulas on your answer sheet, too.”

  • 「式 (しき / shiki)」means “formula”, when it is used in math.
    This kanji was originally a hieroglyphic kanji representing the shape of a (carpentry) tool, meaning a pillar that was steady and solid like a tool. Nowadays, it refers to doing things in accordance with certain rules. Therefore, 「式 (しき / shiki)」 also means “ceremony” or the “style” based on the rules of the person or thing. The meaning changes depending on the context.

Glossary:

  • 解答(かいとう): answer, solution
  • 用紙(ようし): sheet
  • 解答用紙(かいとうようし): answer sheet
  • 式(しき): formula
  • ~も: […] too
  • 書く(かく): to write

【答え(こたえ)】”KOTAE”

Meaning:

answer

Usage:

「答えがわかった人は手を挙げてください。」
(こたえがわかったひとはてをあげてください。)
(Kotae ga wakatta hito wa te o agete-kudasai.)
“Raise your hand if you know the answer.”

  • The verb form of 「答え (こたえ / kotae) is 「答える (こたえる / kotaeru)」, which we pronounce as 「こたえる (kotaeru)」. There are two other kanji that have the same sound as 「こたえる (kotaeru)」 but different meanings:
    • 「応える」: Reward the way the other person works. To react.
    • 「堪える」: To hold back. To endure.
  • The Japanese way of raising hands is to raise one hand straight up with your palm open. Some people may be surprised when they see it for the first time since it is used not only in schools but also in restaurants to call servers. .

Glossary:

  • 答え(こたえ): answer, solution
  • わかる: to understand, to comprehend, to get  
  • 人(ひと): person, people
  • 手(て): hand
  • 挙げる(あげる): to raise
  • ~してください: please do […]