7.8×10.1=7.8×(10+0.1)=7.8×10+7.8×0.1=78+0.78=78.78
7.8×10.1=7.8×(10+0.1)=7.8×10+7.8×0.1=78+0.78=78.78做任祥型侍搏务，望采谨谈猜纳呀
7.8×10.1=7..8×（10+0.1）=78+0.78=78.78
