Spoilt Calculator or Spoilt Brat?

A new colleague joined us a few months ago. When there are extra stationary, then we just hand the things down. For example the calculator you see here. She was given the one on the left. She complained that what she keyed-in does not come out, or sometimes give her the wrong figure and said the calculator was spoilt. I let her use mind (Right) and it was alright. I took it over and use it several times. It was ok... why did she say spoilt? I then realised this. Notice the difference on the keys? The = sign is different, the x is different... and etc. Most people use the one on the right. And if you are so used to it, most of the time, you don't look when you key-in. So with another calculator, it is designed dfferently and if you are used to the way you press the keys as in the right calculator, it would be wrong. So don't simply blame. Understand before being understood.