Let's start from the beginning; there are 10 dimes in each dollar so (10 dimes = $1.00.) (100 dimes =$10.00) (1,000 dimes =$100.00), (10,000 dimes=$1,000.00), (100,000 dimes=$10,000), (1,000,000 dimes =$100,000.00) so there you go. If one million dimes = one hundred thousand dollars then 4 million dimes = four hundred thousand dollars ($400,000.00) hope this helps. Ps; try this one, if there are 100 pennies in each dollar, how many pennies are there in ($10,000.00) ten thousand dollars? Do like I did. (100 pennies =$1.00) (1000 pennies =$10.00) keep going till your done. You can do it! Good luck.