keyboard is typing in numbers istead of character like u is typing 4 how to resolve ?

Recently I faced this issue.

Some keys on my keyboard were typing numbers.
Like 'u' was typing 4 and 'i' was tying 5 instead.

I assumed that Ubuntu has considered the function key is pushed down. And for some reason it has got locked in that position.

The issue however was very simple .

I had by mistake turned the 'NumLk' On.

I disable the Key and the issue was resolved.

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