This challenge is a game for two players. Choose two numbers from the grid and multiply or divide, then mark your answer on the number line. Can you get four in a row before your partner?
Some good suggestions came to us from pupils from many different countries. The answers I used were from a Nature Statistics web site. Mya from Ricards Lodge High School, UK sent in the following ideas for number $7$. She showed a good use of animal knowledge and of mathematical skills.
I think that I might have a solution for number $7$. The question is ... Adult elephants need to drink about $100$/$200$/$400$ litres of water a day. I think that it is ... $100$l. An average adult human should drink about $2$ litres of water a day (coffee and tea don't count). An average ADULT human weights about between $65$/$80$ kg. So the median of the two numbers is $78$, so it should be approximately $1$l per $39$ kg ($39$ is half $78$), for a human. So bearing that in mind if an average adult elephant however weights $4.6$ tons, so converting that into kg that would be $4600$kg.($1$ ton is equal to $1000$kg.) So that is more than $70$ times more than an average human weight ... because $65x70$ would give you $4550$kg - only $50$kg short of $4600$kg. So if you multiply that by $70$ then multiply the amount of water (litres) by $70$ ... so you would get $140$. Rounding it to the nearest hundred you get $100$l !! I think that is right.
Ella, from the same school, sent in these answers:
$1) 500$ million $2) 4.5$kg $3) 13-14$ hours $4) 400$ million $5) 10-14$ years $6) 20$ individuals $7) 100$ litres $8) 170$cm $9) 5$ times as thick $10) 180$kg $11) 8$km $12) 20$ hours
Aadil from Riverside Primary School, UK sent in these good suggestions as answers, many of which were correct:
$1$. $500$ million $2$. $4.5$kg $3$. $18-19$ hours a day $4$. $600$ million $5$. $10-14$ years $6$. $30$ individuals $7$. $200$ litres $8$. $170$ cm $9$. $5$x $10$. $250$kg $11$. $16$km
Betina, Luiza and Katrina from the British School in Barra, Brazil sent in these solutions, written here in the same order as their names:
$1$ $500, 500, 500$ $2$ $4.5, 4.5, 4.5$ $3$ $13-14, 13-14, 13-14$ $4$ $600, 400, 400$ $5$ $18-20, 10-14, 10-14$ $6$ $12, 12, 12$ $7$ $400, 200, 200$ $8$ $220, 170, 170$ $9$ $5, 10, 10$ $10$ $330, 250, 250$ $11$ $8, 8, 8$ $12$ $15, 20, 20$
We also had answers from Germain, Mount Zion School, U.S.A., Julia from TromsØ School in Norway and Harry and Fin from Jebel Ali School in U.A.E.
The answers that I used to set the challenge were:
$1) 500 $
$2) 4$ to $5$
$3) 13$ to $14 $
$4) 400$
$5) 10$ to $14$
$6) 12$
$7) 200$
$8) 170$
$9) 10$x
$10) 180$
$11) 8$
$12) 20$