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

### Instruction:
Josh wants to build a square sandbox that is 3 ft long, 3 ft wide for his son.  He can buy sand in 3 sq ft bags for $4.00 a bag.  How much will it cost him to fill up the sandbox?

### Response:
 Sanduku la mchanga lina urefu wa futi 3, upana wa futi 3 hivyo eneo lake ni 3*3 = <<3*3=9>>9 futi za mraba.
Anahitaji futi za mraba 9 za mchanga kujaza sanduku na anaweza kununua kwenye mifuko yenye eneo la futi za mraba 3. Anahitaji mifuko 9//3 = <<9//3=3>>3 ya mchanga.
Mchanga unagharimu $4.00 kwa kila mfuko na anahitaji mifuko 3 hivyo atalipa $4*3 = $<<4*3=12.00>>12.00 kwa mchanga.