how can I multiply 1,000 times 6.40

Question

6,000                                                                                            

* 6.40

________

 

 

how can i multiply these numbers

Answer 1

1000 times 6.40 shifts the decimal point 3 places to the right in 6.40=6400.

The quick way to find out where the decimal point comes is to multiply 1000 by 6=6000. So we know the answer is going to be 6 thousand and something, hence 6400.

6000 times 6.40 does this, but also multiplies by 6: 38400.