We had many solutions to the numerical questions we posed. From the United Kingdom: Louis, Lucy and Gabriel from Ickford, Taylor from Hillocks, Kieran from Gosforth, Shane and Sameer from Haberdashers, Rohan from Canon Lane.

Charlotte from Laurence Jackson school sent in the following straight-forward ideas that resemble the other solutions sent in.

Solution $1$: count the number of hands and times that number by $5$ which is the number of fingers and thumb on a person's hand.

Solution $2$: simply count the fingers in the picture.

Luke from High Wycombe Maths Master Class sent in,

There are $250$ hands altogether if you count in $5$s it makes it much easier. Hint: the first picture has $30$.

Katrina, Abigail and Aiden from St. Andrew's sent in the solutions clearly as:

Picture $1 - 30$ fingers

Picture $2 - 40$ fingers

Picture $3 - 50$ fingers

Picture $4 - 60$ fingers

Picture $5 - 70$ fingers

We thought the best way to count the fingers was to count the hands in $5$s. You could count pairs of hands in $10$s or count the number of hands and multiply them by $5$ to get the number of fingers.

From the United States of America, solutions were sent in from Conor at Burr Elementary School and Caroline from Estes Hills.

Thank you all for your answers and we welcome any later ones as well.

Did any of you try the last part of the problem, where the challenge was to count using aliens' hands? Do let us know if you've had a go.