Estimate 6896 x 378 by first rounding each number so that it has only 1 nonzero digit
step 1
Round the numbers
6896=7,000 ------> has only 1 nonzero digit
378=400 -----> has only 1 nonzero digit
so
6896 x 378=7,000x400=2,800,000
therefore
the answer is
2,800,000