Mathematics (Form 4)
Chapter 1 - Standard Form
Question:
Round off 365 444 correct to three significant figures.
Solution:
365 444 (Count 3 from the left-hand-side)
Then, look at right beside value 5 which is 4 (4 is less than 5)
So, no need to add 1 to value 5.
Thus, the answer is 365 000.
Question:
Round off 123 567 correct to three significant figures.
Solution:
123 567 (Count 3 from the left-hand-side)
Then, look at right beside value 3 which is 5 (value is equal or greater to 5)
So, need to add 1 to value 3.
Thus, the answer is 124 000.
Question:
Express 0.0000987 in standard form.
Solution:
0.0000987 (count from the (.) to after value 9 which is 5)
9.87 x 10-5 (-ve means the counting is to the right)
Thus, the answer is 9.87 x 10-5 .
Question:
Express 3.41 x 10-2 in single number.
Solution:
3.41 x 10-2 (count 2 from the (.) to the left – because the negative sign)
0.0341 (single number)
Thus, the answer is 0.0341.
In this chapter 1 (Standard form) we have to know the difference between significant figure & decimal points, standard form & single number.
Spread the knowledge, people :)
May we'll be blessed.
So, have fun people!
