(个)
答:他们一共拍了□个。
4+1□ 3+3□ 7+1□
4+2□ 5+3□ 8+1□
4+3□ 7+3□ 9+1□
_
4+49 9-36 7+26 5-12+2
①
②6.875﹣
③372÷25÷0.4
④77×