Australia, like most of the Western world, has over the past five decades been engaged in a giant ideological experiment on how to educate its children to read, write and add up.
During those years, explicit instruction, rote learning and disaggregating learning into bite-sized chunks that can be committed to memory and called upon as necessary fell out of favour. This style of teaching systematically builds one piece of learning on top of another to ensure students master key concepts before progressing to more advanced areas.