Skip counting by 8s
The concept of counting by 8s is used in the table of 8. You can count by fours by adding 8 to the previous number.
If you start with 0 then the numbers counting by eight are
0,8,16,24,32,... and so on.
If you start with 1 then the numbers counting by eight are
1,9,17,25,33,... and so on
Note: If the starting number is odd then the numbers formed by counting by 8's are odd. If the starting number is even then the numbers formed by counting by 8's even.
Skip counting by 8s
Example : Skip counting by 8's
8 : 8 + 8 = 16 ; 16 + 8 = 24 ; 24 + 8 =32 ; 32 + 8 = 40 ; 40 + 8 = 48 and so on.
So if the 1st number is 8 then after counting by 8's we will get 8, 16, 24, 32, 40, 48,...
To find the next number by counting by 8's , add 8 to the given number.
Example 1 : Find the next number of 12 after counting it by 8's.
Solution : Add 8 to 12.
12 + 8 = 20.
So next number will be 20.
Example 2 : Find the next number of 78 after counting it by 8's.
Solution : Add 8 to 78.
78 + 8 = 86.
So next number will be 86.
Example 3 : Find the 5 missing numbers using skip counting by 8's after 30.
Solution : As we have to find the missing number by 8's so add 8 to each number from 30.
1st missing number = 30 + 8 = 38
2nd missing number = 38 + 8 = 46
3rd missing number = 46 + 8 = 54
4th missing number = 54 + 8= 62
5th missing number = 62 + 8 = 70
So the numbers are 38, 46,54,62, 70.
Practice
Q.1 Find the missing numbers.
1) 10,___,___,___,___,___,58
2) 21,___,___,___,___,___,69
3) 46,___,___,___,___,___,___
4) 84,___, 100 ,___,___,___,___
5) ,___,16,___,___,___,___
Q.2 From the above table, write all the numbers starting from 20 counting by 8.
2nd grade math
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