Good news - there's another one.
This maths problem, which was set for EIGHT YEAR OLDS, in rural Vietnam has stumped just about everyone.
The colon symbol, incidentally, is for division and you can only use the numbers once. So yeah, good luck.
Right, so the number you arrive at is 66. You've got to fill in the numbers that add up to that.
Get your copybooks out and remember to show your work.