Simplify the following text for a Grade 5 native English-speaking person.
Original: When the top array is a RAID 0 ( such as in RAID 10 and RAID 50 ) most vendors omit the '' + '' , though RAID 5 +0 is clearer .
Simplified: The calculations for RAID 0 or RAID 1 are simple . However , the calculations for RAID 5 , RAID 6 , or one of the combined RAID levels can be a lot of work .