Zigbee arduino -serial communication help

I am workng on this project
https://www.instructables.com/id/Arduino-Wireless-Animatronic-Hand/

code : https://www.instructables.com/id/Arduino-Wireless-Animatronic-Hand/step6/CODE/

Although the code is there in this link .but i made a completly different code...beacuse using map was not giving precise results so i made mapping function for each flex seperatly.In this code(given in link above) if(Serial.available() >=5) is used...I am working on serial communication for the first time..so I am not able to understand how serial communication using zigbee occur.. Does it send data in string ?
I tried sending 5 numbers by using serial.available.."152 689 356 123 124"
then it printed 1 5 2 6 8. so i think data in string form is send...
here is my code (attached herewith)
I am not using default rx tx pin here....but using 0 and 1 as rx tx also give the same result...
Pleas help me out with what is wrong with this code..(random data is received by this code)

Well i was hoping for solution...but i solved it by myself..so here it is.
if (Serial.available() > 2) // for 3 digit number...if 4 didgit number then serial.avaialable()>3
{
// read the incoming byte:
incomingByte=0;
x=0;
incomingByte = Serial.read();
x= (incomingByte-48)*100; // to convert ascii value to integer digit
if (x>=899) // two digit number 24 is send as 900 + 24 =924
x=x-900;
// Serial.println(incomingByte);
incomingByte = Serial.read();
x=x+((incomingByte-48)*10); // string to int conversion
// Serial.println(incomingByte);
incomingByte = Serial.read();
//Serial.println(incomingByte);
x=x+incomingByte-48;
s1=x;
Serial.println(s1);
//myservo1.write(s1);
}