INTRODUCTION OF SUBTRACTION

Subtraction is one of the four basic arithmetic operations; it is the inverse of addition, meaning that if we start with any number and add any number and then subtract the same number we added, we return to the number we started with. Subtraction is denoted by a minus sign in infix notation.

If addition is the act of putting things together, subtraction is about taking things away. It could be as simple as eating two(2) apples from a pile of six(6) apples. You would wind up with four(4) apples left over. It could also be as complex as figuring out the number of organisms that die each year in a specific ecosystem.

Subtraction is a Mathemathics concept that looks at removing things. You might take away a small piece or a big piece. You will even learn to take away that is greater than at the start. That’s in a bit. You’ll start with something small like two minus one (2-1). If you had two dots and took one away, you would have one left. That idea is the hard of subtraction.

 Interpretations of Subtraction

For many children learning subtraction seems more difficult than learning addition. These could be because Subtraction has several meaning related to real-life situations : -

1. Take away

2. Comparision

3. Completion (Additive)

 Take-away

Subtraction of whole numbers can be applied to types of situations. One of them is take away which is the easiest and natural interpretation of subtraction. The term take away means taking away objects from a group of object. Take away is easy to represent with objects and it is a natural extension of the combination interpretation for addition.

When teaching take away, the teachers need to give equivalent addition and subtraction situations simultaneously in order to reinforce the take away interpretation. Concrete materials demonstrate this interpretation of subtraction more effectively than graphic materials. Story problems in which a subset is removed, lost eaten or the like are usefulin helping children understand this concept. For example, "Jamal has 42 marbles. He gives 7 marbles to his friend. How many marbles does he have left?

 Comparision

The other type is comparative which involves matching one to one objects in two groups of objects. A foundation based on the one-to-one matching test for comparison of two sets is helpful for the children to learn the application. In this comparision interpretation, two sets are compared: "There are 756 chickens and 433 ducks in a farm. how many chickens are there more ducks? " The answer in this subtraction is called the difference and tells how many greater (or lesser) one number is than the other. To teach the comparision situation, teachers guide children in the study of examples in which two sets are compared.

 Completion (Additive)

Besides the comparision, there is another type of subtraction situation if we want to find out the difference between two groups of objects. First, additive focuses on what is needed. It asks, “how much must be added to what I already have to get a certain amount?” For examples Puan Ramlah needs 600 eggs to beke some cakes. She has 380 eggs. How many more eggs does she need? 380 + X = 600. In this question an addend, X is missing. Since addition and subtraction are inverse operations, the missing addend, X can be solved by subtraction: 600 - 380 = X.

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Topic : Subtractionof numbers less than 100

Concept : The Operation of Subtraction can be done by the

process of regrouping

Learning : At the end of the lesson, pupils are able to :

Outcome (a) Perform the operation of subtraction in mathematics sentence throug

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Problem Solving in Subtraction

Solving Mathematics problems are activities involving problems in the form of Mathematics language, including mechanical problems, puzzles, quiz and the use of Mathematics skills in an actual situations.