Questions regarding capex reconciliation from 10-K

Hi Guys, I'm quite new to this and I have a question when trying to reconcile the capex schedule from 10-k for my financial modelling. It seems the number won't match and I appreciate your guidance & thoughts. I'll use Google as an example, and here is the link to its latest 10k: https://www.sec.gov/Archives/edgar/data/1652044/0…

From the Balance Sheet & Cash Flow statement, we have the net PP&E for 2017, Capex for 2018 and Depreciation for 2018. Theoretically, I assume PP&E 2018 = PP&E 2017 + Capex 2018 - Depreciation 2018 (All in dollar amount), listed below

• PP&E 2017:42,383, PP&E 2018: 59,719 (from Balance Sheet)

• Depreciation 2018: 8,164 (from CFO)

• Purchase of PP&E 2018: 25,139 (from CFI)

So it seems like the calculated PP&E 2018 is smaller than the actual PP&E number in the balance sheet, and I haven't factor in the disposal shown on CFS, which will only make the discrepancy larger: 42383 (2017 PP&E) - 8164 (2018 Depreciation) + 25139 (2018 Capex) = 59358 (Calculated 2018 PP&E) 59719 (Balance Sheet 2018 PP&E)

I was wondering what could be the reasons causing this discrepancy. Would really appreciate your time and help, thank you very much!