Understand the concept of adding 1-digit number with the help of objects as well as numbers.
We have learnt that counting forward means addition. Here is a frog moving forward on a number line. The frog starts from number 3 and moves 2 steps forward. The frog is now on 5.
Look at the picture below, in a park Aaron is standing near the pole which has number 6 on it.
He goes forward 3 steps to meet Shelly who is standing near the pole which has number 9 on it.
You have two chocolates. I gave you one. How many will you have? There are 3 chocolates in all. Here the sign = stands for ‘are equal to’. Now two marbles and one marble taken together make three marbles. Thant means if you add 1 to 2, you have 3.
If I give you two chocolates and you have two chocolates, how any will you have? You have now four chocolates. 2 and 2 added together make 4.
Now you have two chocolates and I gave you three. How many will you have? You have 5 chocolates. 2 and 3 added together make 5.
If you have three chocolates and I give you three more, how many will you have? You have now 6 chocolates. 3 and 3 added together make 6.
If Mike has five chocolates and you give him four more, he will have 9 chocolates. Count them. 5 and 4 added together make 9.
In addition we have learnt that when two things and four things are taken together they make six things. The two things and four things are then said to be added together. Thus two and four added together make six.
In arithmetic this is written in a short way as follow:
2 + 4 = 6
The sign or symbol + is called the plus sign and means that the numbers 2 and 4 on either side of it are to be added together.
The sign or symbol = means ‘are’ or ‘is equal to’. Here it tells us that when the numbers 2 and 4 are added together we get 6.
We may read 2 + 4 = 6 as ‘two and four are six’ or we can also say ‘two plus four is equal to six’.
Zero: If you have no chocolates at all, you have zero chocolates.
Zero is written like this 0 and means not any or nothing. If you add 5 to 0, it is still 5. If you add 0 to any number the sum is the same as the number itself.
Regrouping the Numbers:
When the sum of the digits in ones place is more than 9, then we regroup the number in tens and ones.
Lets Regroup the following:
Addition by Regrouping:
Let us add 5 and 8.
Add 5 ones and 8 ones
5 ones + 8 ones = 13 ones
13 ones = 1 ten + 3 ones
Write 3 in ones place and carry 1 ten to tens place.
Questions and Answers on Adding 1-Digit Number:
1. Add the following by Regrouping:
(i) 9 + 6
(ii) 6 + 5
(iii) 9 + 2
(iv) 9 + 4
(v) 9 + 3
(vi) 7 + 3
(vii) 6 + 9
(viii) 7 + 7
(ix) 7 + 8