How to assign a value to buttons, every button would multiply each other and update a text

You could use Unity's newer UI system's Text and Button components to display the value on screen.

1. Create a Text label via the menu. GameObject > UI > Text. This should also create a Canvas. This text object will display our calculated value.

2. Create a Calculator script (CalculatorScript.cs below) and add it as a component to the Text, or another important GameObject.

3. In the inspector, assign the Text component as its 'Result Text'.

4. If the 'Result Value' is 0, multiplying will have no effect, so set it to something else, like 1.

5. Create a Button via the menu by selecting GameObject > UI > Button. Move it around in the scene so that you can still see the Result Text. Or you could Right-Click the Canvas in the Hierarchy and select UI > Button. You can add as many as you like. If you want, you can change the label of a button by going to its child Text GameObject and editing the textbox in the Text component.

6. Add a listener to each button's OnClick event. Select a Button in the Hierarchy and under OnClick() click the little '+' button to add a listener. Where it says 'None (objec...' assign the GameObject that holds the CalculatorScript. Where it says 'No Function', click it and in the drop-down menu select Calculator Script > Multiply (float). Underneath the function drop-down there should now be a number (0). This is the multiplier. Set it to 3, for example.

7. Run the game. The Result Text should display 1 to begin with. When you click a button, it will multiply the value. You can press a button multiple times.

8. ???

9. Profit

CalculatorScript.cs

 using UnityEngine;
 using UnityEngine.UI; // access to Text, Buttons, Canvas, etc
 
 public class CalculatorScript : MonoBehaviour
 {
     public Text resultText; // Assign this in the inspector!
     public float resultValue = 1; // use float for decimal points
 
 
     // initialization
     void Start()
     {
         // update the Text to show the default value.
         DisplayResult();
     }
 
     // updates the displayed text
     public void DisplayResult()
     {
         // if the Text field is assigned in the inspector
         if (resultText != null)
         {
             // convert the double into a string and display as text
             resultText.text = resultValue.ToString();
         }
     }
 
     // CALCULATOR FUNCTIONS
 
     // method function that can be called from other scripts or events
     public void Multiply(float value)
     {
         // multiply the resultValue by this value.
         resultValue *= value;
         // same as: resultValue = resultValue * value;
 
         // update the Text
         DisplayResult();
     }
 
 
     // more example functions
 
     // sets resultValue to 0
     public void Clear()
     {
         resultValue = 0;
         DisplayResult();
     }
 
     public void Divide(float value)
     {
         resultValue /= value;
         DisplayResult();
     }
 
     public void Add(float value)
     {
         resultValue += value;
         DisplayResult();
     }
 
     public void Subtract(float value)
     {
         resultValue -= value;
         DisplayResult();
     }
 
     public void Power(float value)
     {
         resultValue = Mathf.Pow(resultValue, value);
         DisplayResult();
     }
 
     public void Modulus(float value)
     {
         resultValue = resultValue % value;
         DisplayResult();
     }
 
     // etc...
 }

Thank you VERY much!!!! It worked like a charm. Great explenations! The only question that I have is when I multiply a big number it gives a number like so the one below (3.48E+07). What can I do to have a full number displayed?

[1]: /storage/temp/82125-capture.jpg