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

### Instruction:
Martin is casting three bells for the church's belfry. The first bell takes 50 pounds of bronze, the second bell is twice the size of the first bell, and the third bell is four times the size of the second bell. How much bronze does he need total?

### Response:
 Kwanza tafuta ukubwa wa kengele ya pili: paundi 50 * 2 = <<50*2=100>>paundi 100
Kisha tafuta ukubwa wa kengele ya tatu: paundi 100 * 4 = <<100*4=400>>paundi 400
Kisha ongeza kiasi cha shaba inayotumika kwa kila kengele ili kupata jumla: paundi 400 + paundi 100 + paundi 50 = <<400+100+50=550>>paundi 550