#### How to use one helper inside another

Linear helpers can be nested in each other and in block helpers. To use one helper inside another, you need to write it in parentheses **(helper)** instead of curly brackets **{{helper}}**.

For example, you can use it in mathematical calculations, when you need to transfer one calculation to another. For example, you can write expression **10 + 5 − 15** like this:

{{add 10 (subtract 5 15)}}

You obtain zero.

You can embed as deeply as you need:

{{add 10 (subtract 5 (multiply (divide 10 2) 3))}}

And here, you obtain zero again. Mathematically, it can be written as follows: **10 + (5 − ((10 ᛬ 2) × 3))**

In block helpers, for example, we can embed the calculation of client's balance in helper **#****gte**:

{{#gte (subtract balance cost) 0}}
Great, you have enough money to buy this course
{{else}}
It seems that there is not enough money in your account to buy the course
{{/gte}}