int A = 2; 
int B = 3; 
int C = 4; 
int D = 5; 
int E = 6; 
int F = 7; 
int G = 8; 
int switchUpPin = 9; 
int counter = 0; 
int buttonUpState = 0; 
int lastButtonUpState = 0; 

void setup() { 
  Serial.begin(9600); 
  pinMode(A, OUTPUT); 
  pinMode(B, OUTPUT); 
  pinMode(C, OUTPUT); 
  pinMode(D, OUTPUT); 
  pinMode(E, OUTPUT); 
  pinMode(F, OUTPUT); 
  pinMode(G, OUTPUT); 
  pinMode(switchUpPin, INPUT); 
}

void loop() { 
  buttonUpState = digitalRead(switchUpPin); 

  if (buttonUpState != lastButtonUpState) { 
    if (buttonUpState == HIGH) { 
      counter = (counter + 1) % 10;
      showNumber(counter); 
      delay(300);
    }
    lastButtonUpState = buttonUpState;
  }
  delay(50);
}

void showNumber(int number) {  
  digitalWrite(A, LOW);
  digitalWrite(B, LOW);
  digitalWrite(C, LOW);
  digitalWrite(D, LOW);
  digitalWrite(E, LOW);
  digitalWrite(F, LOW);
  digitalWrite(G, LOW);

  if (number != 1 && number != 4)  
    digitalWrite(A, HIGH);  
  if (number != 5 && number != 6)  
    digitalWrite(B, HIGH);  
  if (number != 2)  
    digitalWrite(C, HIGH);  
  if (number != 1 && number != 4 && number != 7)  
    digitalWrite(D, HIGH);  
  if (number == 2 || number == 6 || number == 8 || number == 0)  
    digitalWrite(E, HIGH);  
  if (number != 1 && number != 2 && number != 3 && number != 7)  
    digitalWrite(F, HIGH);  
  if (number != 0 && number != 1 && number != 7)  
    digitalWrite(G, HIGH);   
}