Below is an instruction that describes a task. Write a response that appropriately completes the request in French. Please answer in French.

### Instruction:
 Derek finally gets his own allowance. He puts $2 away in January, $4 away in February, $8 away in March, $16 away in April and follows this savings pattern through to December. How much money does he have to spare and save by December?


### Response:
 Derek double ses économies d'argent de poche chaque mois, donc en mai, Derek a $16 * 2 = $<<16*2=32>>32.
En juin, Derek a $32 * 2 = $<<32*2=64>>64.
En juillet, Derek a $64 * 2 = $<<64*2=128>>128.
En août, Derek a $128 * 2 = $<<128*2=256>>256.
En septembre, Derek a $256 * 2 = $<<256*2=512>>512.
En octobre, Derek a $512 * 2 = $<<512*2=1024>>1024.
En novembre, Derek a $1024 * 2 = $<<1024*2=2048>>2048.
En décembre, Derek a $2048 * 2 = $<<2048*2=4096>>4096 à économiser.