(no subject)

[tinyjo]

So, if we're going to buy expensive schemes to teach children maths, can the providers please make sure that the activities make sense and aren't, you know, wrong or anything.

Say the number: four thousand, seven hundred and eighty-three. Ask children in their groups to write this in figures. Write it on the board to check: 4783. What is the lowest number you can add so that all four digits change? Allow 3 or 4 minutes to try this, then take feedback. (1111 is the lowest number that can be added so that all four digits change, making 5894.) Will this always be the lowest number? Can you find a 4-digit number where all four digits can be changed by adding a lower number? Ask children to explore this, starting by finding different types of number (e.g. multiples of 10 or 100) where a lower number can be added. Ask them to write some general rules (e.g. if the number ends in 9, then the lowest number that can be added to make all four digits change is 1101.)

Just.... No, don't do that! I can't even think of an interpretation that might make that make sense.

Comments

[bluedevi.livejournal.com]

It's surprisingly common, that. The Computing and ICT A-level papers are full of logical flaws. I have a student who's been programming for years and if he thinks about the problems logically, rather than in the sort of vague sloppy pseudocode idiom of the textbooks which does not exist except in the bubble of A-level computing, he gets them wrong.

But, I thought, surely the country is full of people who would delight in coming up with good puzzles for exam papers. I know a good few who would do brilliantly at that. But I imagine they're all programming for good money, not working at exam boards.

[tortipede.livejournal.com]

Speaking of computing, I think I have the solution. Scrap the scheme of work, make use of tinyjo's background in IT, and teach them 6502 Assembler. Once they've got used to ADC¹ they can be introduced to CLC² and BCS³, and voila! — problem solved :)

1 ADd with Carry
2 CLear Carry flag
3 Branch on Carry Set

[celestialweasel.livejournal.com]

And for the next trick, subtraction as 2s complement addition.
Does make multiplication tables easy.
"One one is one"