19世紀の算術の教科書で英語のものだと × を into, multiplied by, times の3つがあるようだけど、 into が古いようだ。
- Dean, Philotus. 1874. The High School Arithmetic: Containig All the Matter Usually Presented in a Higher Arithmetic, Analyzed and Practically Applied : with the Most Approved Models and Analyses : for Public Schools and Academies. A.H. English & Company. https://books.google.co.jp/books?id=ozE46chXlDMC
The sign of multiplication is an oblique cross; thus ×. It indicates that the number proceeding it and the number following it are factors, but does not indicate which is the multiplier or multiplicand. It is read multiplied by, times, or into. (p.40)
次のは10年後ぐらいだけど into が消えている。 そして掛け算に順番がある。
- Fish, Daniel W. 1883. Fish's Arithmetic Number Two: Oral and Written, Upon the Inductive Method. Ivison, Blakeman, & Company. https://books.google.co.jp/books?id=FvwJAAAAIAAJ
The Sign of multiplication is ×. It is read times, or multiplied by.
When placed between two numbers, it shows they are to be multiplied together. Thus, 9×7 is read, 9 multiplied by 7 or 7 times 9. (p.35)
次のも into はない。交換法則があるので、語順通りでも times でいいという説明。
- White, Emerson Elbridge. 1883. A New Elementary Arithmetic: Uniting Oral and Written Exercises. Van Antwerp, Bragg & Company. https://books.google.co.jp/books?id=hKwXAAAAIAAJ
The Sign of Multiplication is ×, and read multiplied by. When placed between two numbers it shows that the number before it is to be multiplied by the number after it. Thus: 6×3 is read 6 multipled by 3.
Note. -- Since the change in the order of the factors does not change the product, the number after the sign may be considered the multiplicand, and the sign read times. 6×3 may be read 6 times 3. (p.100)