Clever Santa
All the girls would like a puzzle each for Christmas and all the
boys would like a book each. Solve the riddle to find out how many
puzzles and books Santa left.
On Christmas Eve the children of one family left a
note for Santa saying that all the girls would like a puzzle each
and all the boys would like a book each. They left Santa this
riddle to solve: The girls have twice as many sisters as brothers and the boys have five times as many sisters as brothers. How many puzzles and how many books did Santa leave for the children? 
Image

What if there was one boy and one girl in the family, could that be right? Why?
What could you try next?
Does your solution fit all the information?
It might be helpful to draw sketches, or jot things down, or use counters for the girls and boys.
Josh, of Alameda School, Ampthill, Beds, sends the following answers:
Santa left five puzzles and two books. Because each girl had four sisters and two brothers, and each boy had one brother and five sisters.
The children of Writtle Junior School (Class SA) want to offer the following solution:We think that Santa would have left 5 puzzles and 2 books based on the following picture:
Image
These show some good thinking. Well done maybe you could try some other activities and send in your solutions.
Why do this problem?
This problem gives children a chance to apply knowledge of
number operations and gain confidence in using a trial and
improvement approach.
Key questions
What could you try first?
How will you record what you do?
Does that fit all the information?
Possible extension
Children could make up their own version of this problem for a
friend to solve.
Possible support
Using differently coloured counters to represent boys and
girls might help some children access this problem  it will allow
them to refine their answer try without being afraid of
writing down something that turns out to be wrong.