The first equation sayd that 2 spider webs are equal to 16 so

so the spider web has a value of 8
then we have that a candy minus the spider web is equal to 9 so:

then we have that a spider web times a cat minus a candy is equal to 7 so:

then we have that the gloves plus a cat is equal to 11 so:

Then we have that a bat plus a glove minus a candy is equal to 23 so:

Then we have that a bat plus the product between a cat and a pumpkin is equal to 21 so:

sipider plus web times pumpkin equal to 21 then:

and finally the las equation has to be

So the message is:
