The number of words that Carl can type per hour is 50 * 60 = <<50*60=3000>>3000 words.
The number of words that Carl can type in 4 hours is 3000 * 4 = <<3000*4=12000>>12000 words.
The number of words that Carl can type in 7 days is 12000 * 7 = <<12000*7=84000>>84000 words.
#### 84000