Counting forwards or backwards by a number other than 1
Example: Skip counting by 3 is: 3, 6, 9, 12, 15, 18, ...
Try dragging the marbles:
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。