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'Children at Large' printed from https://nrich.maths.org/
Why do this
problem?
This problem
can be solved by either trial and improvement or, more formally, by
making a set of two simultaneous equations. For this reason, it
could be used as a method of introducing or revising simultaneous
equations.
Key questions
How are you going to work on this? Are you going to use trial
and improvement or try to make a set of simultaneous
equations?
Would a number line for the children's ages help you?
Would it be useful to write the initial information as
simultaneous equations?
Can you get two equations involving just two of the
unknowns?
Whose ages are even and whose odd?
What combinations are possible for Tom's and Sally's
ages?
Why not try a number or Tom's age and see how it works
out?
Possible extension
Learners could go on to a similar problem such as
Thasan's
Dream.
Possible support
Suggest jotting down the useful information a number line for the
children's ages.