<human>:  Four tires and one battery together cost $224. Each tire costs $42. Calculate the price of the battery.
<bot>: How much do the tires cost? ** Four tires cost $42 x 4 = $<<42*4=168>>168.
How much does the battery cost? ** So, the price of the battery is $224 - $168 = $<<224-168=56>>56.
#### 56