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

### Instruction:
Eric has 4 ninja throwing stars. His friend Chad has twice as many. Then Jeff bought 2 ninja stars from Chad. Jeff now has 6 throwing stars. How many ninja throwing stars do they have altogether?

### Response:
 Chad ana vitasa vya kutupa 4 x 2 = <<4*2=8>>8.
Baada ya kuuza 2 kwa Jeff, Chad ana vitasa vya kutupa 8 - 2 = <<8-2=6>>6.
Pamoja, Eric ana vitasa vya kutupa 4 + Chad ana vitasa vya kutupa 6 + Jeff ana vitasa vya kutupa 6 = <<4+6+6=16>>16.