Counting By Twos

Counting by twos is called skip counting. Here the each number is 2 more than the previous number. In counting by 2's sometimes we get all odd numbers and sometime all even numbers, it depends on the first number. If the first number is odd then counting by 2's we will get all odd numbers. If the first number is even then counting by 2's we will get all even numbers.

Example : Skip counting by 2's

1; 1 + 2 = 3 ; 3 + 2 = 5 ; 5 + 2=7 ; 7 +2 = 9 ; 9 + 2 = 11 and so on.

So if the 1st number is 1 then after skip counting by 2's we will get 1, 3, 5, 7, 9, 11,...

To find the next number by counting by 2's , add 2 to the given number.

Example  1 : Find the next number of 15 after counting it by 2's.

Solution : Add 2 to 15.

15 + 2 = 17.

So next number will be 17.

Example  2 : Find the next number of 82 after counting it by 2's.

Solution : Add 2 to 82.

82 + 2 = 87.

So next number will be 87.

Example 3 : Find the missing numbers using skip counting by 2's. 34,___,____,____,____,44.

Solution : As we have to find the missing number by 2's so add 2 to each number.

1st missing number = 34 + 2 = 36

2nd missing number = 36 + 2 = 38

3rd missing number = 38 + 2 = 40

4th missing number = 40 + 2 = 42

So the numbers are 34, 36,38,40,42, 44.

Practice on counting by twos

Q.1 Find the missing numbers.

1) 10,___,___,___,___,___,___,24

2) 21,___,___,___,___,___,___,35

3) 46,___,___,___,___,___,___,60

4) 84,___, 88 ,___,___,___,___

5) ,___,16,___,___,___,___