Final answer:
In healthcare, needle gauges range from the small 30 gauge to the larger 18 gauge, where a smaller number represents a thicker needle. Choice of needle gauge is crucial for patient comfort and procedure success. The example of counting nails by weight is unrelated to needle gauges.
Step-by-step explanation:
In healthcare, needle gauge sizes range from small diameters to larger ones. The gauge system is somewhat counterintuitive because a smaller gauge number indicates a thicker needle, while a larger number means a thinner needle. The smaller gauges start at around 30 gauge, which is very thin, and typically used for intradermal injections and tuberculin tests. Moving towards larger needles, you would find, for instance, a 25 gauge needle often used for subcutaneous injections, then a 21 gauge needle, which is commonly used for intramuscular injections. Finally, you might encounter an 18 gauge needle, which is quite thick and often used for blood donation because it allows blood to flow more rapidly. It's important for healthcare professionals to choose the appropriate needle gauge for the procedure to both minimize patient discomfort and ensure the procedure's efficacy.
Regarding the example provided, it is unrelated to needle gauges but illustrates an estimation method using weight. To estimate the number of nails in a hardware store box, you would subtract the weight of the empty box (213 g) from the combined weight (1340 g), resulting in a weight of 1227 g for the nails alone. Dividing this by the weight of a single nail (0.450 g) would give you the total number of nails in the box.