a ppt is here

• addition and subtraction
• multiplication
• division

a ppt is here

the centre number can only be changed by one of the four allowable steps to get to the outer numbers

there should be no repeated numbers in any of the boxes

the powerpoint involves

• decimals
• directed numbers
• fractions

sometimes the relationship does hold even though it usually doesn't

a curious relationship that works for a restricted set of numbers

intended to practice many number skills

thanks to David Wells

powerpoint

work out the rule
find as many solutions as you can
find the missing number
what relationships can be found connecting the three outside numbers to th middle one?

a ppt is here

the mid-point on a line is 3
what numbers could be either side of it?

varying the gap:

• simple numbers
• fractions
• negative numbers
• decimals
• big numbers
• in general...

these resource sheets seek to involve decimals and fractions in the task 'both ways'

from the Shell Centre materials on Decimals (1983)

a slightly simplified problem - because real life is too complicated


be wary of units

students could total up the cost of the rails plus the posts
this site (for example) could be used

you might want to include galvanised nails
and maybe a delivery cost

you might also ask them to create an approximate cost formula, for 'n' meters of perimeter

as far as I'm aware (i) Q4 has two solutions (maybe more):