①99.7×13+ ×13
②12.78﹣(1.17+2.78)﹣3.83
③910÷1.3×0.7
④67× ﹣9÷1.25+ ×2
( )
( )
642÷6= 0.9×99+0.9= 1.25×80= 2.5÷0.01=
÷ = 2﹣ ﹣ = 3﹣ ﹣ = ( ÷ )×30=