Using Integer in HashMaps

So I am trying to use HashMaps by specififying:

HashMap totalAtt = new HashMap<String, Integer>();

But when I try to add two of the Integers, it gives me an error saying bad operand. How can I add the integers I retrieve from this HashMap without a compiler error or warning?

Edit: Replaced some code, no longer getting compiler error, rather warning of unchecked or unsafe operations

public HashMap<String, Integer> getAttrib()
{
    HashMap<String, Integer> totalAtt = new HashMap();

    //Creates key values and initializes them to 0
    totalAtt.put("strength", 0);
    totalAtt.put("dexterity", 0);
    totalAtt.put("constitution", 0);
    totalAtt.put("intelligence", 0);
    totalAtt.put("wisdom", 0);
    totalAtt.put("charisma", 0);

    HashMap<String, Integer> sAtt;

    for(Sprite s: itemList)
    {
        //iterates through items and counts their attributes
        sAtt = s.getAttrib();

        totalAtt.put("strength", totalAtt.get("strength") + sAtt.get("strength"));
        totalAtt.put("dexterity", totalAtt.get("dexterity") + sAtt.get("dexterity"));
        totalAtt.put("constitution", totalAtt.get("constitution") + sAtt.get("constitution"));
        totalAtt.put("intelligence", totalAtt.get("intelligence") + sAtt.get("intelligence"));
        totalAtt.put("wisdom", totalAtt.get("wisdom") + sAtt.get("wisdom"));
        totalAtt.put("charisma", totalAtt.get("charisma") + sAtt.get("charisma"));
    }

    return totalAtt;
}

From Sprite class:

public HashMap<String, Integer> getAttrib()
{
    return attrib;
}