1) Let the fifth one be X, then the next three are X- 1, X-2 and X-3. The first four are y.

X+(X- 1)+(X-2)+(X-3)+4Y = 10(X-2)+(X-3)

Y=(7X- 1)/4-4

Because both X and Y are numbers, X=3, Y= 1 or X=7, Y=8.

So, this phone number is1113210 or 88887654.

(2) Let the fifth digit be X, then the last three digits are X+ 1, X+2 and X+3 respectively, and the first four digits are the same. Let them be y, so there are

X+(X+ 1)+(X+2)+(X+3)+4Y = 10(X+2)+(X+3)

Y=4+(7X+ 1)/4 .

Because both X and Y are numbers, X= 1 and Y=6.

So, this phone number is 666 1234.

To sum up, Xiaoming's home number may be113210, 8887654 or 666 1234.