order of magnitude

order-of-magnitude的词性：
n.（名词）

1. An estimate of size or magnitude expressed as a power of ten:
数量级：以10的表示的大小或幅度的大约值：

Earth's mass is of the order of magnitude of 10²² tons; that of the sun is 10 ²⁷ tons.
地球质量的数量级是10²²吨 ；太阳的则是10 ²⁷吨

2. A range of values between a designated lower value and an upper value ten times as large:
等级：处于相差10倍的两个数值之间的那一段值的范围：

The masses of Earth and the sun differ by five orders of magnitude.
地球与太阳的质量相差五个数量级