3.7×1.83.7 4.2÷1.54.2 6.21÷0.016.21×100
照如图方式继续摆,第20个图形要用根小木棒,摆第个图形要用126根小木棒。
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+ ×
⑤
⑥