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

### Instruction:
Ms. Hatcher teaches 20 third-graders and a number of fourth-graders that is twice the number of third-graders. Her co-teacher asked her to substitute for her fifth-grade class that has half as many students as the number of third-graders. How many students did Ms. Hatcher teach for the day?

### Response:
 Bi Hatcher alifundisha wanafunzi 20 x 2 = <<20*2=40>>40 wa darasa la nne kwa siku.
Alifundisha wanafunzi 20 / 2 = <<20/2=10>>10 wa darasa la tano kama mwalimu mbadala kwa siku.
Hivyo, Bi Hatcher alifundisha wanafunzi 20 + 40 + 10 = 70 kwa siku.