2.3042.340 7.56×10756÷10
(36+64)×5450 420-210÷70(420-210)÷70
6.926.298 380-163-37380-(163+37)
7.828.27 4200÷354200÷7×5
①73000÷125
②9000÷8÷125
③6200÷(5×62)
④510÷34+ 17
⑤45×71+29×45
⑥54×63+38×54-54