( 1 )a+b=0.00...024+0.00...05=0.00...029(注意数位对齐,2009个0)
(2)a×b=0.00...024×0.00...05=0.00...0120
(根据小数乘法法则,a×b积的小数位数应该有(2009+2)+(2010+1)=4022位,4019个0)
(3)a÷b=0.00...024÷0.00...05=24÷5=4.8(根据小数除法法则,将a、b的小数点同时向右移动2011位,正好是24÷5,而商不变.)
( 1 )a+b=0.00...024+0.00...05=0.00...029(注意数位对齐,2009个0)
(2)a×b=0.00...024×0.00...05=0.00...0120
(根据小数乘法法则,a×b积的小数位数应该有(2009+2)+(2010+1)=4022位,4019个0)
(3)a÷b=0.00...024÷0.00...05=24÷5=4.8(根据小数除法法则,将a、b的小数点同时向右移动2011位,正好是24÷5,而商不变.)