单词	tally mark
释义	Tally Mark A way of keeping count by drawing marks. Every fifth mark is drawn across the previous 4 marks, so you can easily see groups of 5
随便看	oblique cone oblique cylinder oblique prism oblique pyramid oblong obtuse angle obtuse triangle octagon octahedron octal odd number odds odometer one dimensional opaque open curve open interval open sentence operation operator opportunity cost opposite numbers opposite side or order of magnitude

数学辞典收录了1200条数学词条，基本涵盖了常用数学知识及数学英语单词词组的翻译及用法，是数学学习的有利工具。