Praise be to Allah.al-hamdu lillaah.
The division of the inheritance in the case you mention is as follows:
An eighth of it is due to the wife, since the father had children, as indicated in the verse (intrepretation of the meaning):
"And if you have children, then to them (the wives) is due an eighth of what you have left behind, after [paying] any amount specified in the will or any loans due." (surat al-Nisaa':12).
The remaining seven-eighths (7/8) is divided into 11 equal portions. Each male among his children is entitled to two portions and each female one portion, as per Allaah's specification (interpretation of the meaning):
"Allaah has enjoined upon you with regards to your children that the [entitlement of] the male is twice that of the female." (al-Nisaa':11).
For example, let's suppose the man in question left property and wealth with a total worth of $88,000, and he does not owe payment on any loans and did not specify any special requests or instructions to make particular donations in his will. Thus, the division would be as follows:
For the wife, an eighth, 1/8 of 88,000 which is $11,000.
The remaining 77,000 is divided into 11 equal portions, 1/11 * 77,000 = $7,000
So each son is entitled to two portions, or 2 * 7,000 = $14,000
And each daughter is entitled to $7,000.