Final answer:
President Roosevelt wanted Congress to increase the number of supreme court justices from nine to fifteen.
Step-by-step explanation:
Based on the information provided, President Roosevelt wanted Congress to increase the number of supreme court justices from nine to fifteen. His proposal was to add a new justice for each sitting justice over the age of seventy, in order to make the court more efficient and to counter the court's decisions that had declared many of his New Deal economic programs unconstitutional.