#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16,2);

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  Serial.println("Calculator for addition");
  lcd.init();
  lcd.backlight();
}

void calculator() {
  // put your main code here, to run repeatedly:
  Serial.print("Enter 1st number > ");  
  int num1 = Serial.readString().toInt();
  lcd.setCursor(0,0);
  lcd.print(num1);
  Serial.print(num1);
  lcd.setCursor(5,0);
  lcd.print("+");

  Serial.print("Enter 2nd number > ");  
  int num2 = Serial.readString().toInt();
  lcd.setCursor(8,0);
  lcd.print(num2);
  Serial.print(num2);

  int result = num1+num2;
  lcd.setCursor(0,1);
  lcd.print(result);

  delay(1000);
  lcd.clear();
}

void loop(){
  delay(2000);
  calculator();
}