Lots of people sent in solutions for this one.

Becky Lindsay (Age 8 from Wheelers Lane Junior School, Birmingham, England) gave one of the best explanations ...

"I found this quite an easy puzzle because I know my times tables well. I soon spotted that 56, 28, 63 and 49 were all in the seven times table and later found out that 105 was. I also noticed that 100, 18, 65, 9 and 76 were not in the seven times table. I then worked out that 14 and 70 were".

As Susannah Keene (Age 9, Headington Junior School, Oxford) says, "A ziffle is a multiple of 7".

Joshua Tattersall, (age 10, of Ampthill, Bedfordshire), Emma Pearson (Cambridge), Matthew Smith and Year 3 from Hethersett Old Hall Juniors also sent in correct solutions.