Keeping in mind the rules for significant digits, what is the product of 0.8954 m and 2.98 m?

3.240576

Explanation:

There are various ways of doing multiplication this is one of them

The wording "keep in mind the rules for significant digits" implies that we are to use these to show where the decimal place goes by approximating the answer. Then conducting the exact calculation.

Consider 0.8 as 8  

×

1

10

3

×

8

×

1

10

=

2.4

So the solution is some where a bit above 2.4

Lets just use the numbers

Multiply both 0.8439 and 3.84 by 1000 to get rid of the decimal place. This makes thing more straight forward. So we end up with:

8439

×

38400

Split up the 38400 into 30000+ 8000 + 400

30000

×

8439

=

253170000

.

8000

×

8439

=

.

67512000

.

.

400

×

8439

=

.

.

3375600

−−−−−−−−−  

←

Add

.

324057600

By our approximation we are expecting the form of

2.4

+

small amount

So the answer is  

3.240576

Check by calculator:  

0.8439

×

3.84

=

3.240576