Accurate measurements are important because precise amounts are required for reactions to take place, for a recipe to turn out and to keep correct records of a measurement. When measurements are not accurate, this provides incorrect data that can lead to wrong or even dangerous conclusions or results.
When measuring, measurements that are not accurate provide data that is wrong. If something is based off an object or individual's weight, having an inaccurate weight is dangerous. For example, a prescription drug that has a weight-based dosage could have a dosage that is too low to treat a condition. If a lab experiment calls for a specific amount of a chemical, measuring the wrong amount may result in an unsafe or unexpected outcome.