SG chevron_right Primary 5 chevron_right Fractions

My P5 son's teacher asked him to solve this maths question using "drop down model". I googled for "drop down model" but could not find. Anyone knows what is it?Thanks.

SG chevron_right Primary 3 chevron_right Number and Algebra

I was so sure my answer was right. Anymore can tell me?

SG chevron_right Primary 5 chevron_right Number and Algebra

SG chevron_right Primary 4 chevron_right Number and Algebra

Pls ignore the diagrams. But if u read the question, do u think all 3 persons had $80 after James gave away the money or do only Daryl and Celine had $80.

SG chevron_right Primary 3 chevron_right Measurement

Pray tell, If I don't use 18cm X 12cm....Cos that is Primary 4 syllabus ...then how to find out the answer using Primary 3 method???