importance: 5

---

# Create a calculator

Create an object `calculator` with three methods:

- `read()` prompts for two values and saves them as object properties with names `a` and `b` respectively.
- `sum()` returns the sum of saved values.
- `mul()` multiplies saved values and returns the result.

```js
let calculator = {
  // ... your code ...
};

calculator.read();
alert( calculator.sum() );
alert( calculator.mul() );
```

[demo]
