Based on what I know., primary schools do not learn algebra with more than one unknown. I don't know. I am just a student. Correct me if I am wrong

That used to be the case in the past (maybe 10 years agoa and before)

'Units and parts' is very commonly taught nowadays in primary schools, in addition to the model drawing techniques.

It's just another name for simultaneous equations but without the usage of x and y.

Simpler questions which require this method appear as early as P5.

Eg.

3 blouses and 2 skirts cost $50.
4 blouses and 7 skirts cost $97.

Students are expected to apply elimination method by first multiplying the sets and making either item the same number.

This could be done by model drawing or by the usual algebraic equation way, with the use of the first letter of the item name as the abbreviation.


Eg.

3B + 2S = 50 → 12B + 8S = 200

4B + 7S = 97 → 12B + 21S = 291


Then comparing the two,

21S - 8S = 13S

291 - 200 = 91

91 ÷ 13 = 7

A blouse costs $7.

Skirt price can be found subsequently.

Sound funny. Anyway thx yr effort. No diff to me. It is still algebra. :(

Yes, it is effectively that.

But algebra is not formally taught to primary school students.

This is basically a subtle preparation and seeding for secondary school.

They also use models and unit drawings to symbolise those unknowns.

It is more pictorial than abstract (which secondary school math is more of)

Eg.

⬛⬛⬛ ⬜⬜

←←←$50→→

⬛⬛⬛⬛⬜⬜⬜⬜⬜⬜⬜

$97