One quite major change is that, from now on, mathematics and science will be taught in English from the start of primary school, whereas in the past, Malay was the medium of instruction for the first three years of primary school. Table 3 on page 41 of the SPN21 book published by the Ministry of Education shows this:
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The only relevant material I can find anywhere in the book concerning this issue is the top of page 15, which says:
"SPN21 also addresses concerns on:
- The need to sustain and strengthen performance in Bahasa Melayu
- Low English Language proficiency
- Poor performances in mathematics and the sciences"