freeCodeCamp/curriculum/challenges/chinese/10-coding-interview-prep/project-euler/problem-217-balanced-numbers.md

---
id: 5900f4461000cf542c50ff58
title: 'Problem 217: Balanced Numbers'
challengeType: 5
forumTopicId: 301859
dashedName: problem-217-balanced-numbers
---

# --description--

A positive integer with k (decimal) digits is called balanced if its first ⌈k/2⌉ digits sum to the same value as its last ⌈k/2⌉ digits, where ⌈x⌉, pronounced ceiling of x, is the smallest integer ≥ x, thus ⌈π⌉ = 4 and ⌈5⌉ = 5.

So, for example, all palindromes are balanced, as is 13722.

Let T(n) be the sum of all balanced numbers less than 10n.

Thus: T(1) = 45, T(2) = 540 and T(5) = 334795890.

Find T(47) mod 315

# --hints--

`euler217()` should return 6273134.

```js
assert.strictEqual(euler217(), 6273134);
```

# --seed--

## --seed-contents--

```js
function euler217() {

  return true;
}

euler217();
```

# --solutions--

```js
// solution required
```