You can touch and slide to mark out each scarecrow's area, which covers as many squares as the number on the scarecrow.
There must be only one scarecrow in each area.
An area's border will turn blue when it's the right size, or red if it's too big.
It will also turn red if there's more than one scarecrow within it.
So...crow for it!
Answer for 'Scarecrow Coverage 21'
The answer is as follows.