Change Number into number (#46168)
Change Number into number (#46168)

It was causing the following error:

```
The left -hand and right hand side of an arithmetic operation must be of type 'any', 'number' or an enum type
```

See also: https://www.typescriptlang.org/docs/handbook/declaration-files/do-s-and-don-ts.html#number-string-boolean-symbol-and-object
georgemarshall/DefinitelyTyped,mcliment/DefinitelyTyped,markogresak/DefinitelyTyped,georgemarshall/DefinitelyTyped,georgemarshall/DefinitelyTyped,georgemarshall/DefinitelyTyped