Oracle SQL Summing Values From Two Different Tables

Hey all so I am trying to add to (or subtract from) a column of different values based on a separate column in another table. Here is a example of what I am tying to do:

Table 1: (Current Inventory)

ItemName  |  Quantity
----------|----------
Baseball  |         5
Football  |        10
Jersey    |         3

Table 2: (New Shipment)

ItemName  |  Quantity
----------|----------
Baseball  |        70
Football  |       100
Jersey    |        50

How can I update my all items in Table 1 (current inventory) by adding Table 2's quantity to them?