This lesson will help you to:
- Understand the concept of addition using a 10 x 10 grid.
- Add using 2 digit numbers.
- Add using 3 digit numbers.
- Apply addition to real life situations.
Real Life Examples
- Addition helps in calculating the money spent for buying commodities from the market.
- Addition helps in calculating measurements like distance
- The opposite sides of a dice always add up to seven.
Quick concept Review
Addition is combining smaller sets to a bigger single set. Facts of daily life help us in understanding the concept better.
More about Addition
Addition is one of the basic four operations.
- It is denoted by the symbol"+". For example: 4 added to 9 can be written as 9 + 4.
- The numbers that are added are called addends.
- A 10 x 10 number grid is a helpful tool to add 2-digit numbers.
- Some words that denote addition are "in all", "total", "sum" and "altogether".
- Addition can be done in different ways s
Counting in tens: 55 + 23 = 55 + 10 + 10 + 3 = 75 + 3 = 78
- To make addition easier it is important to regroup the numbers.
For example: 421 + 379
Add the ones = 1 + 9 = 10
Add the tens = 20 + 70 + 10 = 100
Add the hundreds = 400 + 300 + 100 = 800
Add 800 + 100 + 10 = 910
Similarly for four digit numbers first of all add one digits, then tens, then hundreds and then thousands respectively.
PROPERTIES OF ADDITION
- Commutative or Order Property of Addition: Two or more than two numbers can be added in any order
- 290 is same as 1290 + 2130.
- Associative property of addition: Sum of three or more number is not affected by their grouping e.g.
1200 + 1400 + 1300 = (1200 + 1400) + 1300 or 1200 + (1400 + 1300).
- Sum of zero (0) and number is the number itself. This zero is called identity element e.g. 7000 + 0 = 0 + 7000 = 7000.
- The ‘+’ and ‘-‘symbols first appeared in print in mercantile arithmetic published in Leipzig in 1489.