Final answer:
The food handler made a mistake in not ensuring all parts were accounted for when reassembling the slicer machine, leading to potential safety hazards and machine malfunction.
Step-by-step explanation:
The mistake the food handler made when putting the slicer machine back together was not accounting for all of the components, leading to extra screws or a missing screw. This can happen when reassembling machines after cleaning or maintenance. The slicer is expected to have the same number of parts after reassembly as it did before being taken apart. Missing or extra parts suggest an incorrect reassembly which could lead to machine malfunction or pose a safety hazard, especially when working with chemicals or sharp components like knives.
The food handler made a mistake by not properly reassembling the slicer machine after cleaning. They either had extra screws or were missing a screw that was originally part of the machine. This mistake can cause the machine to not function properly, posing a safety risk to the handler and potentially affecting the quality of the sliced food.