## Monday, 28 November 2011

### Number Sequence in Third Grade

Hello my dear friends, today we will learn the basic concepts of mathematics that we study in the primary class i.e. Third grade. Students in this class are very small and in this they don’t implement any concepts, but simply learn the concepts. Let’s start with the basic of mathematics and basic of Grade III. Numbers. What you understand by numbers. Numbers are the starting of mathematics that moves through the mathematics. Numbers are the mathematical object used for the purpose of count and measure. In math, the definition of number has been extended over the years and years. In mathematics numbers are of several types like zero, negative, rational, irrational (see irrational numbers examples here), and complex. Also try to know what are prime numbers?

In grade III kids learn the simple numbers like, 1,2,4,100… and with this they  learn how to write these numbers in the word form. Like mathematical 1 is written as one. In the same way 2 is written as two and 14 is written as fourteen. Writing numbers in word form is simple 1 to 10 numbers are so easy to write as one, two, three, four, five, six, seven, eight, nine and ten. In the double digit number like 11, 21, 31, 41 they all are written as eleven, twenty one, thirty one, forty one and so on. The numbers with one’s are written as shown above. And the number having zeros in last place are written as 30- thirty, ‘ty’ is the main thing that we use at the end of numbers with zero. 20 is written as twenty, 30 thirty, 40 is forty and so on.. This is applicable for 2 digits number only.

The method of expressing the other number is same like if we have 20- twenty then we can write the other number of after 20 and up to 29 as twenty one, twenty two, twenty three….twenty nine. In the same way we produce for 30 to 39 and so on. After, the initial number start putting numbers from 1 to nine as it is. The first three digit number i.e. 100 is written as hundred and after this again the same process starts like 101 hundred one, 102 hundred two and so on up to 999.

In the Grade IV students learn the concept of numbers in more depth and remaining things. Now, move to the other concepts related to numbers that students study in the same Grade i.e. Grade III. Even and odd numbers, even numbers are those numbers which are exactly divisible by two. The numbers that come in table of two are even numbers. And one important thing is that all even numbers end with zero, two, four, six and eight. Let’s see few examples of Even numbers. 2,4,6,8,10,12,14,16,18,20,22,24,26,28,30, 32,34, 36, 38 an so on.
These numbers are even as they are containing 2,4,6,8, and 0 at the end.
Now, the other type of numbers i.e. odd numbers.  Odd numbers are those numbers that are not exactly divisible by two. Odd number includes, 1,3,5,7,11,13,15, and so on.

Now, a question for you is 27 an odd number or even?  Yes, it is an odd number as it is not fulfilling any condition of even number. Now, here is other example, 51, 76, 89, 64, 65, 98. Find the even numbers out of the given series?

Answer: in the above question, we have 76, 64 and 98 as the even number. Because 76 contain 6 in last place, 64 have 4 and 98 is having 8 in the last place. And in the above section we have described that number ending with 2,4,6,8 and zero are even number. In the number system of the Grade III kids, also learn the skipping count puzzles. In skipping count puzzle students learn how to skip the same number in any sequence of number. Suppose we have 4,6,8,10 then what is the difference in them or we can say they are skipping by which number. In this series we are skipping two in between all the numbers of the series. Let’s see the other example of the skipping counting, 3,6,9,12,15... In this we are skipping three numbers at a time.

With the numeric value students of Grade III also learn word problems related to skip counting. Let’s have an example of this like John began at 68, he skip-counted until he reached 93. Could he have been counting by fours?
Answer: we know that John started 68 and skip- counted until he got to 93. We want to find out if he could have been counting by fours. Start counting like John, and on doing so we get, 68 +4 = 72 then again add 4 in 72,
72 + 4 = 76,
76 + 4 = 80,
80 + 4 = 84.
84 + 4 = 88,
88 + 4= 92,
92+ 4 = 96.
Thus the answer of the question is no. as if he proceeds like this then he will reach to 92 or 96 but not on 93.

Let’s have one more word problem of the skip counting to understand its concept properly so that my dear kids don’t get any problem in future and can easily solve the entire question related to skip counting.

Question: Alien start counting at 50 and finish when she reached to 80 what are the numbers that she go through while she was counting until she reached to 80 when she is counting by skipping 2.
Answer: let’s start with 50 and add 2 to each term every time so until we reach 80 so that we can easily find the total number of steps evolved to reach 80,
50+2 = 52,
52 +2= 54,
54 + 2 = 56,
56 + 2= 58,
58 +2 = 60,
60 +2 = 62,
62 + 2 = 64,
64 + 2 = 66,
66+ 2= 68,
68 +2 =70,
70+ 2 =72,
72 +2 =74,
74 +2 = 76,
76 + 2 = 78,
78 + 2 =80.
Thus, we can say that total step used to reach to 80 from 50 is 15. In this way students can learn how to skip the numbers and reach to other number.

In the above example I explained you the skip count in increment way in the same way we can skip in numbers in the reversed way. In this we are performing addition in the reverse we perform subtraction and do the work in the reverse way.  Let’s see one example to see the skip numbers in reverse way.

Question: Jas start counting in reverse way and from 33 and end with she reach to 6 then calculate the number of steps and the term that she skipped.
Answer, in this she is coming from higher to lower so we start subtracting the number, 3.
33- 3= 30,
30 – 3, 27,
27 – 3 = 24,
24- 3= 21,
21- 3 = 18,
18 – 3 = 15,
15 – 3 = 12,
12 – 3 = 9,
9 – 3 = 6.

In this we move 9 steps back to reach the level of 6 from 30 and in each step we have to subtract 3. In this students learn how to skip the numbers and with this they learn addition and subtraction easily. Skip count is something like game which is not so hectic and hard to learn. Students easily learn addition and subtraction with its help.

With this kids also learn number sequence in this class III. Number sequence is very simple concept as in this kids only learn how to determine the number which is missing in any sequence, which is very simple to adding or subtracting a number. Suppose we have a sequence as: 4, 14,_, 34, 44. in this we have to determine the number in the blank space? For doing such we see the difference between the other numbers like difference between 4 and 14,
14-4 = 10,
In the same way we find difference between 44 and 34,
44 – 34 = 10,
The difference between all the numbers is 10 so , add 10 in 14 and we get the number of blank place,
14 + 10 = 24,
To cross check the answer you can now subtract 34 from 24 and if difference is same as others then answer is right,
34 -24 = 10,
Let’s have one more example of this so that you can understand the problem and its concept properly.
Question: 5, 10, 15, _, 25, 30, _?
In this question use the same method that we have used in the previous question if we subtract 10 from 5,
10- 5 = 5,
In the same way on doing this operation with other numbers we get 5, so add 5 to 15 and then to 30 and we get the missing numbers.
15 + 5 = 20,
30 + 5 = 35.
In this way you can easily determine the numbers which are missing in the sequence. For more help, take online help and enjoy math.

In upcoming posts we will discuss about Problems related to Angles in Grade III and math help online blog. Visit our website for information on ICSE syllabus for business studies