Simplify the following text for a Grade 6 native English-speaking person.
Original: There are an estimated 125,000 to 150,000 hippos throughout Sub-Saharan Africa ; Zambia ( 40,000 ) and Tanzania ( 20,000 â `` 30,000 ) possess the largest populations .
Simplified: There are about 125,000 to 150,000 hippos in Sub-Saharan Africa . Zambia ( 40,000 ) and Tanzania ( 20,000 -- 30,000 ) have the most hippos .