All ACT Math Resources
Example Question #15 : Even / Odd Numbers
Which of the following expressions is odd for any integers and ?
All the expressions can be even for some combination of and
The key here is for any integers and , that means that no matter what you set and equal to you will get an odd number. An odd number is not divisible by 2, also it is an even number plus and odd number. The only expression that satisfies this is . will always be even, so will , but is always odd so the combination gives us an odd number, always.
Example Question #16 : Even / Odd Numbers
For this problem, align and solve by adding the ones digit , tens digit , and hundreds digit . This also means that you have to add to the in the thousands place to get .
Example Question #1 : How To Add Even Numbers
Find the sum of 12 and 42.
Rewrite the question into a mathematical expression.
Add the ones digit.
Add the tens digit.
Combine the tens digit and the ones digit. The answer is .