follow principles of estimation to find an approximate value.
round each number so that there is one nonzero digit do not find the exact value
4423 * 4997
thanks in advance

Question

follow principles of estimation to find an approximate value.
round each number so that there is one nonzero digit  do not find the exact value
4423 * 4997
thanks in advance

ybarrap · Answer

4423*4997 is about (4000 + 423)(5000) =(4000*5000 + 423*5000) which is about 20,000,000 + 2,000,000=22,000,000

Compare this to the actual answer of 22,101,731. 

Not too bad!

ybarrap · Answer

Note that I used 400 instead of 423 above

anonymous · Answer

by rounding down to the nearest digit?

ybarrap · Answer

Yes

anonymous · Answer

much appreciated thank you nicely explained

ybarrap · Answer

NP