Why Estimation Comes First
In real life before you touch a calculator, you should already know the answer. Roughly tight as a human
Estimation is well check. If you are calculating anything like the area of a soccer field and your estimate says about 5,000 square feet but your calculator will display 50,000, you are likely hit the wrong key of the calculator. Estimation take place .
In today's lesson, I will teach you how to solve significant figures ,and work on estimation as whole. I will make this easy for you since Brainimatic Series has the simple her own method of teaching. This is another branch of mathematics that deals with numbers greater or less than 1.
This where most people go wrong in estimation. When they see a calculator screen showing 2.34897116 and write down every digit. That is not in a tight term; that is very wrong.
Significant figures (sig figs) are those digits in a measurement that carry meaning. They tell a story about your tools.
This is all about round off a particular number to the nearest one. Nearest can be in many ways. What are these numbers, they are very simple to know,am I so much believe that you know them. They are :
Number to the nearest whole number 23.4
Number to the nearest ten 26
Number to the nearest hundred 271
Number to the nearest ten thousand and so on. These are mechanism involve in this package. This simply means what we will discuss is based on rounding numbers to their level.
Note
0 1 2 3 4 = 0
5 6 7 8 = 1
Rule 1: The above key is what we should consider first before we begin our journey. The rule say, any number from zero to 4 is 0, any number from 5 to 9 is 1.
Rule 2: The second rule is that, if your ask to round off any to nearest whole number, if the number is from 0 to 4 that number automatically become 0. But if the number is from 5 to 9, the number become 1
Rule 3: The number 3 is that, if your ask to round off any number to the nearest 10. If the number that will round off is less that 5 that number become 0, but if the number is 5 to 9 that number become 10.
Rule 4: The next rule is, any number that will round off numbers to the nearest 100, if that number is less than 5, automatically that is 0, but if the number is 5 to 9 that number is 100. Etc....
Another term you should know is Decider. Their duty is to round off numbers.
Rounding off numbers to their nearest whole number
Example 1
Round off the following numbers to their whole number;
(a) 2. 54
(b) 56.46
(c) 46.13
Solution
(a) 2. 54
= 2. 54
= 3
5 is the decider. 5 become 1( Base on rule 1)
2 + 1 = 3
(b) 56.46
= 56 . 46
= 57
4 is the decider, the 4 become 0. (56 + 0= 56)
(c) 46.13
= 46.13
= 46
1 is 0 ( 46 + 0)
Rounding off numbers to their nearest 10
Round off the following numbers to their nearest 10;
(a) 456
(b) 34
(c) 1263
Solution
(a) 456
= 456
= 460
Any number at the right side is the decider, sotherfore, 6 is the decider to 5. Remember, 6 is in place of tens, 5 become 50 , while 6 become 10.
50 + 10
= 60
4 is thousand, and our taget is 10, not hundred.
(b) 34
= 30
4 is the decider, and its 0.
30 + 0
= 30
(c) 1263
= 1263
= 1260
3 is the decider, and its 0.
Rounding off numbers to their nearest 100
Round off the following numbers to their nearest 100;
Example
(a) 2891
(b) 4715
(c) 1145
Solution
(a) 2891
= 2891
= 2900
9 is the decider, and the 9 become 100,
800 + 100
900. The 8 is in place of 10, so is 800. I believe you understand what I mean.
(b) 4715
= 4715
= 4700
1 is the decider, remember 1 is 0
700 + 0
= 700
The 7 is in place value of 100. It's 700
(c) 1145
= 1145
= 1100
The same thing happened in the above working, 4 is the decider, and its 0.
That is what we have today, in our next post, I will teach you how to solve significant figures of any kind. I believe you that understanding on how to round off numbers.
Home work
Round of the following numbers to the nearest 10, 100 and 1000
(a) 2416
(b) 4913
(c) 2106
(d) 6538
(e) 4116
This is Brainimatic Series lesson, for more information contact us through contact us page.
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