①
②
③
④
⑤
⑥
261﹣99= 17÷34= 2.1+0.79= 80×125%=
÷36= 38.38÷38= +×0= ×3÷×3=
① ×[0.75﹣( ﹣25%)]÷1.25
②6.37×1.25﹣1 +4.63×125%
③7.09× +0.225×6﹣60%×0.64
④ ×3+ ×25+ ×