###Human: Joey has 30 pages to read for history class tonight. He decided that he would take a break when he finished reading 70% of the pages assigned. How many pages must he read after he takes a break?, ### Assistant: Joey will take a break after 30 * 0.7 = 21 pages
Joey will have to read 30 - 21 = 9 pages more. 
 So the answer is :  9