Number Span: free digit span memory test, forwards and backwards

What is Number Span?

Digits flash one at a time. Type them back in order, then backwards. Clear both and the next string is one digit longer. The classic digit-span test of working memory, as a game.

Number Span is a free working memory game based on the digit span test. Digits flash on the screen one at a time. Type them back in the same order, then type the same string backwards. Clear both and the next string gets one digit longer.

Forwards measures how much you can hold; backwards adds a mental operation on top, which is why it's harder. Most adults hold about seven digits forwards and five or six backwards. Your score is the longest string you cleared both ways.

At a glance

Category

Memory

Difficulty

Medium

Play time

2–3 min

Price

Free, in your browser, sign-up optional

How to play

Watch

Digits flash one by one, starting with three.

Type

Type them back in order, with your keyboard or the keypad.

Reverse

Then type the same digits backwards, last one first.

Grow

Both right: one more digit. A miss costs a life and shows the answer. Your score is your longest span.

Strategy and tips

Chunk it

Group digits in twos or threes, like a phone number: 4-8-1 becomes 481.

Say them

Repeat the digits silently as they flash. The inner voice is a memory buffer.

Backwards from chunks

Reverse each chunk, then the order of chunks.

Stay calm on misses

A miss gives a new string of the same length, not a reset.

Short sessions

A few runs a day beat one long session.

Why play Number Span?

Working memory is the notepad your brain uses to follow a conversation, do mental maths or remember a code for a few seconds. The digit span task is one of the oldest ways to stretch it.

Frequently asked questions