Primary School Mathematics : Domains of Subjects

Domains of Subjects

Here we, for the sake of convenience, divide the contents of the primary mathematics into the following five domains :

Number and Arithmetic
- Natural Number
- Rational Number (Fraction, Decimal)
Quantity and Measurement
Proportional Relation
Data Processing
Geometry

As to the first two domains, let us confirm that the number and the quantity cannot be discussed separately. In fact, when we use a system of number, we are treating a system of quantity.

This combination of a system of number and a system of quantity (for example, the weight) occurs in a following way :

This diagram is read :

"B is N times A"
"The ratio of B to A is N"
"With A being the unit of measurement, the value of B is N"

The content of the domain of "Proportional Relation" is the "proportional relation/function between two systems of quantity". A general form of this subject is "Relation and Function".
Other relations/fuctions might be picked up. But they are not important here by themselves.

Remark 1

Introducing another weight A as the unit
Getting the number N which satisfies the following relation :

measured value

Remark 2

	Number of Apples	Length	Area	Volume	Weight	Time	Temp- rature	Money	2-dim real vector	......
Natural Number	.	.	.	.	.	.	.	.	.	.
Rational Number	.	.	.	.	.	.	.	.	.	.
Real Number	.	.	.	.	.	.	.	.	Multiple	.
Complex Number	.	.	.	.	.	.	.	.	Multiple & Rotation	.
......	.	.	.	.	.	.	.	.	.	.

The number and the quantity occurs as a set