Summarize this article in one sentence.
If your meat has been in the freezer longer than you can remember, you'll probably want to toss it, just to be on the safe side. If not, there are some telltale signs your food has gone bad. The meat looks discolored. There's a nasty smell coming from the packaging. The package shows signs of freezer burn (ice on the inside). Though it is possible to defrost meat without a container, you'll save yourself a lot of clean up time by using one. Typically, glass bowls are the best, safest containers to use in a microwave. If you're planning to use a plastic container, check out the original packaging to make sure it's safe for microwave use. Some other items considered unsafe for the microwave include brown paper bags, aluminum foil, and single-use plastic containers (ex: the kind that take-out food comes in). Basically, if you're not sure, don't use it. If the meat is still in its original packaging, it probably has a label that tells you exactly how much it weighs. If it doesn't, you'll need to weigh it yourself. The best tool for weighing meat is a kitchen scale, which gives more specific weights (down to fractions of a lb/kg) than bigger scales. Many materials used to package frozen meats should definitely not be microwaved, so be sure to toss everything but the meat itself before you begin cooking.

Summary:
Check the meat for signs of spoilage. Find a microwave-safe container. Weigh the meat. Remove the meat from its wrapper.