(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

but...

[jinty]

that question is expecting an answer where all the numerals increase, whereas you could easily get a new number where all the digits change without all increasing...

Re: but...

[phlebas.livejournal.com]

The bit at the end about numbers ending in 9 would suggest otherwise. I'd guess this is aimed at a level where your 'easily' doesn't apply.

Yes

[jinty]

it's a badly-phrased question is my point.

Re: but...

[tinyjo.livejournal.com]

I would expect our year 4s to figure out number bonds to the next thousand would do it - not all of them but about half our class.

Re: but...

[tinyjo.livejournal.com]

Yes, exactly. It's the fact that they categorically state an incorrect fact ("(1111 is the lowest number that can be added so that all four digits change, making 5894") which bugs me most - adding 217 makes a number where all the digits change!