addition - Why decimal add up incorrectly in mysql -

i want retrieve data based on condition in database :

select * `chatroom` 5.27680128733988 + 100.488135965769 = 105.764937253109

this produced 0 result when there know value of addition 105.764937253109

to prove addition equals 105.764937253109 update 1 of row table correct value :

update `chatroom` set `latitude`= 5.27680128733988 + 100.488135965769 room_id = 2

the updated column shows result of addition 105.764937253109 why when try select results in first database query, shows 0 data found?

thank you

because 5.27680128733988 + 100.488135965769 = 105.7649372531089; you're missing "8"

Ben