Estimate the following using general rule:
$$12,904 + 2,888$$
$$12,904 + 2,888 :-$$
By rounding off to thousands, $$12904$$ rounds off to $$13000$$ and $$2822$$ round off to $$3000$$
$$13000$$
$$+3000$$
$$........$$
Total $$16000$$
The addition of these two number is $$16,000.$$