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You should keep this in the back of your mind in the event that you end up showing a HAZUS Summary Report to an eagle-eyed audience.
When viewing tabular data in a HAZUS Summary Report, please note that ALL numbers are rounded (up or down) to the nearest displayed digit, and that includes subtotals and totals!
This means that the total displayed in a Summary Report may not match the sum of all the numbers that make up the total. This is due to a rounding artifact in the HAZUS Summary Reports.
For example, imagine a Shelter Summary report that showed the following displaced households in your study region:
County A: 5
County B: 1
County C: 0
Study Region Total: 7
5 + 1 + 0 = 6, not 7, so what is going on here?
Chances are that the HAZUS data behind your Summary Report looks something like this:
County A = 4.9 (which was then rounded up to 5)
County B = 1.4 (which was then rounded down to 1)
County C = 0.3 (which was then rounded down to 0)
Total = 4.9 + 1.4 + 0.3 = 6.6 (which was then rounded up to 7)
In this case, the rounded total shown in the Summary Report (7) is different from the straight sum from the rounded county numbers (5+1+0=6).
Fortunately, this rounding artifact is rarely an issue. However, if you ever create a HAZUS Summary Report for a relatively small disaster, you may run into a case where the data for every county in your study region is displayed as 0, but the Study Region Total is 2. This, again, is due to rounding artifacts, and is not an arithmetic error in HAZUS.