考點:奇數(shù)與偶數(shù)的初步認識,合數(shù)與質(zhì)數(shù)
專題:數(shù)的整除
分析:在自然數(shù)中,不能被2整除的數(shù)是奇數(shù).除了1和它本身外,沒有別的因數(shù)的數(shù)為質(zhì)數(shù).除了1和它本身外,還有別的因數(shù)的數(shù)為合數(shù).據(jù)此可知,最小的奇數(shù)是1,最小的質(zhì)數(shù)是2,最小的合數(shù)是4.合數(shù)中最小的奇數(shù)是9.
解答:
解:最小的奇數(shù)是1,最小的質(zhì)數(shù)是2,最小的合數(shù)是4.合數(shù)中最小的奇數(shù)是9.
故答案為:1,2,4,9.
點評:明確奇數(shù)、質(zhì)數(shù)、合數(shù)的意義是完成本題的關(guān)鍵.