FORM 4 Mathematics: STANDARD FORM
After years of teaching, I found that most of the student do not know how to use their scientific calculator to input the standard form in a proper way, or maybe nobody ever taught them there is such a function in the calculator. (One thing that I always don't understand is that why most of the teachers do not teach their students to use scientific calculator.)
For example, for a standard form such as 2.5 x 105, most of the student will key in 2.5 x 10^5. This is not wrong but is an improper way of keying standard form. The proper way to key in this number is 2.5E5. The function "E" is the Exp or exponential function, which is stand for x10( ).
Example:
1.6 x 1018 = 1.6E18
2.7x 10-15 = 2.7E-15
Anyway, what is the problem? Why we need to care about whether it is proper or improper?
Well, first of all, using E is easier than using x 10^ .
Second (and the most important), using x 10^ can easily cause mistake when we calculate the operation of standard form, especially a calculation involve division.
Let's look at this example.
2.5 x 106 ÷ 5 x 105 =
If you key in 2.5 x 10^6 ÷ 5 x 10^5, you will get a wrong answer. If you key in
2.5E6 ÷ 5E5 =, then your answer is correct.
We can see that using x 10^ may cause mistake if you don't use it with care, but using E (Exponent) do not have this problem.
Thanks skkwee for sharing with everyone. Source: forum.one-school.net/viewtopic.php?f=21&t=7
After years of teaching, I found that most of the student do not know how to use their scientific calculator to input the standard form in a proper way, or maybe nobody ever taught them there is such a function in the calculator. (One thing that I always don't understand is that why most of the teachers do not teach their students to use scientific calculator.)
For example, for a standard form such as 2.5 x 105, most of the student will key in 2.5 x 10^5. This is not wrong but is an improper way of keying standard form. The proper way to key in this number is 2.5E5. The function "E" is the Exp or exponential function, which is stand for x10( ).
Example:
1.6 x 1018 = 1.6E18
2.7x 10-15 = 2.7E-15
Anyway, what is the problem? Why we need to care about whether it is proper or improper?
Well, first of all, using E is easier than using x 10^ .
Second (and the most important), using x 10^ can easily cause mistake when we calculate the operation of standard form, especially a calculation involve division.
Let's look at this example.
2.5 x 106 ÷ 5 x 105 =
If you key in 2.5 x 10^6 ÷ 5 x 10^5, you will get a wrong answer. If you key in
2.5E6 ÷ 5E5 =, then your answer is correct.
We can see that using x 10^ may cause mistake if you don't use it with care, but using E (Exponent) do not have this problem.
Thanks skkwee for sharing with everyone. Source: forum.one-school.net/viewtopic.php?f=21&t=7
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