<human>:  James wants to build a 16-foot by 20-foot quilt. He uses patches that are each 4 square feet. The first 10 patches cost $10 each and then each patch after that cost half as much. How much do the patches for the quilt cost?
<bot>: How many square feet is the patch? ** The patch is 16*20=<<16*20=320>>320 square feet
How many patches does James need? ** So he needs 320/4=<<320/4=80>>80 patches
How much did the first 10 patches cost? ** The first 10 patches cost 10*10=$<<10*10=100>>100
How much do the remaining patches cost? ** He gets a discount on the next 80-10=<<80-10=70>>70 patches
How much do the remaining patches cost? ** They each cost 10/2=$<<10/2=5>>5
How much do the patches for the quilt cost? ** So in total they cost 70*5=$<<70*5=350>>350
How much did the patches for the quil cost? ** That means in total he paid 100+350=$<<100+350=450>>450
#### 450