void setup() {
Serial.begin(9600);
}
void loop() {
int a=10;
int b=4;
Serial.print("add a+b=");
Serial.println(a+b);
delay(1000);
Serial.print("sub a-b=");
Serial.println(a-b);
delay(1000);
Serial.print("mul a*b=");
Serial.println(a*b);
delay(1000);
Serial.print("dev a/b=");
Serial.println(a/b);
delay(1000);
}