I found this helpful:

for attracting underwater frogs
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step 1

check your TADPOLES number if it is the same with FROGLET number.. IF tadpoles number is bigger you have more froglets available to visit your garden

step 2 sum ADULT UW FROGS number        (XXX)
                  SPOOOKY UW FROGS number    (XXX)
                                                             --------------
          =        TOTAL FROGS                        (XXX)                             

step 3      FROGLETS (XXX)   -   TOTAL FROGS (XXX)  = the number of frogs you have available to come in your garden

ex   80 froglets - 71 total frogs = 9 available frogs to come

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for attracting land frogs
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step 1

check what you have spotted in other gardens

ADULT UW FROGS number  (XXX) AND SPOOKY FROGS number (XXX) = TOTAL FROGS SPOTTED

step 2

see how many sets are availabe

TADPOLES number       (xxx)
FROGLETS number       (xxx)
TOTAL FROGS number  (xxx)