The multiplication of numbers is commonly seen in technical English. Therefore it is essential to have thorough understanding of those expressions. Yet dispute has long been haunting the translation of multiplication of numbers.
Here are the main expressions.
A is n times as great（long，much，…）as B.
A is n times greater （longer， more，…）than B.
A is n times the size （length， amount，…）of B.
A 的大小（长度，数量，……）是 B 的 n 倍，或， A 比 B 大（长，多，……）n-1 倍
This book is three times as long as （three times longer than，three
times the length of ）that one.
这本书的篇幅是那本书的 3 倍（即长两倍）。
increase to n times
increase n times／n-fold
increase by n times
increase by a factor of n
增加到 n 倍，或，增加 n-1 倍
The production of various stereo recorders has been increased four times as against 1977.
“by n times”的意思是“用 n 数乘”。
如 15 increased by 5 times 是 15×5 = 75 之意，75 与 15 相比显然是增加了四倍，而不是五倍。