一、小数点“搬家”。1.把20.5的小数点向左移动两位后,再向右移动一位,这时的小数是()。2.把一个小数先扩大1000倍,再缩小10倍后是24.9,这个小数原来是()。3.把1.502的小数点去掉,它的值就()()倍。4.把100.82的小数点移到最左边,这个数就()。5.把0.35扩大10倍是(),去掉小数点是(),缩小10倍是(),改写成以千分之一为单位的数是()。 First, the decimal point “move ”. 1. Move the decimal point of 20.5 to the left by two digits and then the right by one digit again. The decimal point here is (). 2 to expand a 1000-fold first, and then shrink 10-fold after 24.9, the original decimal (). 3. The 1.502 decimal point removed, its value () () times. 4. Move the decimal point of 100.82 to the left, which is (). 5. To expand the 0.35 is 10 times (), remove the decimal point (), reduced 10 times (), rewritten as the number of one-thousandth is ().