直接写出得数: 0.64+= 0.032= 5﹣2%= 45÷7﹣3÷7= 25÷5= 0.8÷0.002=
估算:675500-510900≈703530-205120≈695540-578905≈503543-105780≈595500-478900≈735433-205540≈
估算:601530-205120≈687240-595905≈512500-145280≈586520-475450≈735433-205540≈595450-471246≈
估算:865500-578900≈803433-205000≈455464-205000≈866546-578900≈70123-105000≈553543-305540≈
口算:831500-554900=25650+21560=95410+21260=1249000-249000=2580010-2580000=246000+154000=
口算:865500-578900=95400+21560=258000-158000=125000+125000=3571000-2571000=2514980-2414980=