The Year 6 Number stream of the new mathematics Curriculum contains a notable content descriptor:
multiply and divide decimals by multiples of powers of 10 without a calculator, applying knowledge of place value and proficiency with multiplication facts; using estimation and rounding to check the reasonableness of answers (AC9M6N06)
There’s not too much to say about such absurdity. At Year 6. We do want to comment upon, however, a companion elaboration:
explaining the effect of multiplying or dividing a decimal by 10, 100, 1000 … in terms of place value and not the decimal point shifting
Should students develop some proper understanding of place value, a sense of its meaning beyond the mechanics? Of course. But should students also be forbidden from “explaining” multiplying or dividing by ten in terms of “the decimal point shifting”? Life is way too short for such fusspottery.
Of course no one explains multiplication by ten in terms of moving the decimal point. Rather, the expression is used to describe the visual effect of that multiplication. It is a short, clear and useful description. Except for overlording pedagogical pedants.
The new Curriculum is bloated with such nonsense, where some justifiable concern for understanding is worried to death, where straight-forward description is forbidden, is shoved aside in order to engage in meaningless ritual. David Treeby’s term for this absurdity is Rote Learning, and it fits perfectly.
The foundation of mathematical understanding is solid practice of well-chosen exercises. With a good sense of how the mathematics works then, and only then, can students begin to seriously ponder and appreciate why the mathematics works the way it does. But the curriculum writers care nothing for practice. As long as the children don’t stray from The Path, as long as they chant the The Sacred Words, all is good.