This question is about scientific notation, in complete math smart 9 book.
The population of Canada was about 3.2 x 10^7. There was about 77% of Canadians living in cities and towns.
a. How many Canadians lived in cities and towns in 2005? = For this question, I got 2.464 * 10^9 but the actual answer was 10^7. Why and how is that possible?
b. The population of Canada in 2007 was about 4% more than that in 2005. What was the population in 2007? = I've got the same problem as in the question a. The answer was 3.328 * 10^7, but I got 3.328 * 10^9
Could you please help me with these questions?
a. [3.2 x 10^7] x 77/100 =24,640,000 =2.464 x 10^7. Count the number of digits from right to left until you get to the last digit, which is 2. You must NOT include this last digit(2) in the count. If you do that right, you will see that there are only 7 digits, which is the exponent or power of 10 in your scientific notation.
b. [3.2 x 10^7] x 1.04 =33,280,000 =3.328 x 10^7. You count exactly the same as above and you should get the right answer.
+129842 Note : 77% = 77/100 = .77 ....and since we can multuiply in any order, we have
3.2 * 10^7 * .77 =
3.2 * .77 *10^7 =
2.464 * 10^7
For the second problem......a 4% increase means that we can multiply the 2005 population by 1.04 and we have
3.2 * 10^7 * 1.04 = again, we can multiply in any order
3.2 * 1.04 * 10^7 =
3.328 * 10^7
Note that we didn't have to do anything to the 10^n part of the scientific notation !!!!
You didn't read the answer carefully. I said "to the last digit, which is 2" You don't count it, because the decimal point goes in front of it. Then you count EVERYTING to the right of the decimal point. So, 35,000,000 would look like this in scientific notation: 3.5 x 10^7.
