Answer:
2.40 is the missing number
Step-by-step explanation:
Since digits of eight subtracted by nine can't give you 10 you have to plug in decimals. Start from two and try 2.10, 2.20, 2.30, and 2.40. Then select the one that gives you closest to 19. It would be 2.40; furthermore, this gives you 19.2 and rounding it would be 19. 19-9= 10. Hope this helps! =0)