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# how to call a method on a variable

I am working on one of the challenges and I am not sure how to solve it, please help: We need to figure out the tax amount when the tax percentage is 7.5 percent. Call the method calculateTaxes on the variable item and assign the result to a new variable named taxes.

struct.swift
```struct Expense {
var description: String
var amount: Double = 0.0

init (description: String) {
self.description = description
}
func calculateTaxes (percentage: Double) -> Double{
return (self.amount * (percentage/100))
}

}
var item = Expense(description: "Spent money")
item.amount = 100.00

item.calculateTaxes (item.amount * 7.5/100)
var taxes = calculateTaxes
```

Hi Paula,

To call a method on a variable, the syntax is 'variable.method()'. In this case, our variable is item and the method is calculateTaxes, so it's item.calculateTaxes(), with our argument inside of the parentheses. We'll store the result of this method call statement to our taxes variable (since this method statement will return the value that we want to store in the taxes variable.)

```var taxes = item.calculateTaxes(item.amount * 7.5/100)
```

Hope this helps!