We buy a block of baking chocolate of five Kg around ten pounds. When we want to use the chocolate it's always a hassle to break off a piece. It's a block five cm thick ( two inches). I need a easier way to break off just the amount we need. thank you
I think you will get better suggestions on Seasoned Advice (the Stack exchange for professional and amateur chefs).
But apart from chopping off a large chunk by using a knife/chisel and a blunt tool like a hammer, you could also heat the knife and melt-cut the piece you want (I don't see a problem with doing it, although there might be, because of the nature of chocolate).
I can think of 2 options.
Add your own indentations. That is, figure out the size you need, and score it to that size with a serrated knife (like a large bread knife). It should break off very easily that way.
Another option is to chip the whole giant block into small pieces, which you can store in tightly-sealed plastic bags or plastic containers. Then, when you need a certain weight, just pour out the right amount of the small chips you made.