【答案】
【分析】
解這個(gè)問題主要用“湊”的辦法,但不應(yīng)該盲目的湊,每相鄰兩個(gè)數(shù)之間都有四種運(yùn)算符號(hào)可填(加、減、乘、除),在湊的時(shí)候,一邊試,一邊估計(jì)結(jié)果,不斷調(diào)整.我們有:
2 - 2 ÷ 2 + 2 - 2 = 1
2 + 2 - 2 + 2 - 2 = 2
2 + 2 ÷ 2 + 2 - 2 = 3
2 × 2 × 2 - 2 × 2 = 4
2 - 2 ÷ 2 + 2 + 2 = 5
2 + 2 + 2 + 2 - 2 = 6
2 + 2 ÷ 2 + 2 + 2 = 7
2 × 2 × 2 + 2 - 2 = 8
2 × 2 × 2 + 2 ÷ 2 = 9
2 + 2 + 2 + 2 + 2 = 10