# Understanding the bait-taken calculations

The bait-taken calculations can be a bit confusing to begin with, however, once you understand them it makes calculating the quantity of bait used within your project much easier.

When entering records in the field, the bait taken is automatically calculated by trap.nz based on the figures you have supplied.

There are some key points to know are :

* Bait taken is calculated from bait remaining on the current record minus the calculated bait remaining from the previous record with the additions and subtractions

* Records with the same date and time are invalid and will make calculations unreliable

* Bait-taken calculations are updated every few minutes, so may take some time to recalculate after changes are made

When working out the bait taken added you start at the bottom of the table and work up, In the case below 1.    On  01/11/22 the bait station had 0.200kg (1) added 2.   On the next visit (working up the table) 0.134kg had been taken (2), leaving 0.066kg remaining (3). The remaining old bait (0.066kg) (4) was removed and fresh bait supplied 0.200kg (5)                                                  [0.200 - 0.134 =0.066] {0.066 - 0.066 = 0.000}  [0.000 + 0.200 = 0.200] 3. The following visit  0.150kg had been taken (6) leaving  0.050kg (7), the 0.050kg was removed (8) and another 0.200kg was added of fresh bait (9)

[0.200 - 0.150 = 0.50] {0.050 - 0.050 = 0.000} [0.000+ 0.200 = 0.200] 4. On the next visit, 20/01/23 the same quantity was taken as the previous visit so the calculations are the same as above 5. On the final visit showing  24/01/23,  0.115kg had been taken (10) leaving 0.085kg(11)  remaining, the 0.085kg (12) was removed and 0.200kg (13)  of fresh bait added                                                                                                [0.200 - 0.115 = 0.085] {0.085 - 0.085 = 0.000} [0.000+0.200=0.200] 