<human>:  David and Dasha went to the carnival, where there are 9 rides. Each ride costs 2 ride tickets at $2 per ticket. You can also buy a ride bracelet for $30 which gives you 9 rides. If David buys a ride bracelet and Dasha buys tickets, and they ride all 9 rides, how much money does David save?
<bot>: How much does each ride cost? ** Each ride cost 2 x $2 = $<<2*2=4>>4.
How much do all 9 rides cost? ** All 9 rides cost $4 x 9 = $<<4*9=36>>36.
How much does David save? ** By bathing the ride bracelet, David saves $36 - $30 = $<<36-30=6>>6.
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