Sets and Addition Sentence
A set is a group of objects. We call the objects in each set as elements . ADDITION SENTENCE An addition sentence has many parts. The number we add are called the addends . The answer is called the sum . The symbol "+" is called the plus sign . It means we add or put together. The symbols "=" is called the equal sign . We write the sum after this sign. There are two ways of writing an addition sentence. We have the horizontal and vertical ways of writing addition sentences When we add using the number line, we always start from 0. The Commutative or Order Property Addition means that changing position of places of the addend will not change the sum/ The Associative or Grouping Property of Addition means that changing the position or places of the addends will not change the sum The Zero Property of Addition means that any number added to zero is always equal to the same number. We can add two-digit numbers horizontally by writing their expanded form...