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## Main Question or Discussion Point

Hi,

I am using a textbook which asks: How far does a commercial jetliner (1046 kilometers/hour) go in 35 milliseconds?

The reason this isn't in the homework section is because I answered this correctly, but apparently not using the book's version of how to handle significant numbers. Maybe you can help me.

here are the calculations I did

1046 kilometers/hour * (1000 meter/1 km) * (1 hr/3600000 ms) * (35 milliseconds)

or

1046 * 1000 / 3600000 * 35 = 10.169444444444444444444444444444 -> rounded to 10 meters since 35 has 2 significant figures and the answer should have no more significant figures in a multiplication/division operation than the number with the least significant figures in it.

The answer given in the textbook is 10.2 (3 significant figures!). Why is the textbook giving 3 significant figures to the answer when a number in the multiplication/division operation clearly has no more than 3 significant numbers in it, but rather has 2. Everywhere I look, this seems to break the rule. I am told everywhere that the answer must not be more than the number in the operation with the least significant figures.

I am using a textbook which asks: How far does a commercial jetliner (1046 kilometers/hour) go in 35 milliseconds?

The reason this isn't in the homework section is because I answered this correctly, but apparently not using the book's version of how to handle significant numbers. Maybe you can help me.

here are the calculations I did

1046 kilometers/hour * (1000 meter/1 km) * (1 hr/3600000 ms) * (35 milliseconds)

or

1046 * 1000 / 3600000 * 35 = 10.169444444444444444444444444444 -> rounded to 10 meters since 35 has 2 significant figures and the answer should have no more significant figures in a multiplication/division operation than the number with the least significant figures in it.

The answer given in the textbook is 10.2 (3 significant figures!). Why is the textbook giving 3 significant figures to the answer when a number in the multiplication/division operation clearly has no more than 3 significant numbers in it, but rather has 2. Everywhere I look, this seems to break the rule. I am told everywhere that the answer must not be more than the number in the operation with the least significant figures.

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