Something Is Missing... - Set 1

Explanation: You will be given addition problems with one of numbers missing, such as 18 + ___ = 24.  Break the problem into 2 small parts so the problem can easily be completed as a 'mental math' problem.  

Examples:

18 + ___ = 24   Break the problem into 18 + ___ = 20 and 20 + ___ = 24.  For 18 + ___ = 20, the 'missing' number is 2.  For 20 + ___ = 24, the 'missing' number is 4.  Together, 2 + 4 = 6, so the 'missing' number for 18 + ___ = 24 is 6.  Easy 'mental math' steps!

___ + 19 = 23  Break the problem into 2 easy parts: ___ + 19 = 20 and 20 + ___ = 23.  The two 'missing' parts are 1 and 3, and 1 + 3 = 4, so the 'missing' part for ___ + 19 = 23 is 4.  Easy 'mental math' steps!

Directions: Strive to be able to find the sum of the 'missing' parts, then strive to increase your speed.  Good luck and enjoy the challenge!