⅀ Double-struck N-ary Summation

How to type Double-struck N-ary Summation on Mac / Windows / Linux?

Windows: Use the Emoji Panel (Win + .) or copy/paste ⅀.

macOS: Use Character Viewer (Control + Command + Space) and search by name, or copy/paste.

Linux: Use the Character Map app or a Compose key sequence, then paste into your app.

How to type Double-struck N-ary Summation on iOS / Android?

On iOS, long-press the globe/emoji key and search in the symbol picker, or paste the symbol.

On Android, open the symbols keyboard or use your app’s character panel, then paste.

How to add Double-struck N-ary Summation in HTML?

Use an HTML entity, a decimal code, or a hex code. All of them render the same symbol in your markup.

<span>&#8512; symbol</span>

<span>&#8512; symbol</span>

<span>&#x2140; symbol</span>

How to add Double-struck N-ary Summation in CSS?

CSS escapes work inside the content property. This is most useful with ::before or ::after.

.symbol::after {
  content: "\2140";
}

<span class="symbol"></span>

How to add Double-struck N-ary Summation in JavaScript / JSON?

Use Unicode escapes in strings for a stable, language-neutral representation.

const symbol = "\u2140";
console.log(symbol);

{
  "symbol": "\u2140"
}

How to add Double-struck N-ary Summation in URL / Query string?

Use percent-encoding. In JavaScript, use encodeURIComponent.

https://example.com?q=%E2%85%80

How to add Double-struck N-ary Summation in Word / Google Docs / Excel?

In Word or Google Docs, go to Insert → Symbol (or Special Characters) and search the Unicode name.

In Word, you can type 2140 and press Alt+X to convert it.

=UNICHAR(8512)

Encoding notes

UTF-8 and UTF-16 byte sequences are listed above for developer tools, debugging, or data pipelines.