Heather knits 4 cm each night has many nights will heather have to knit to get 28 centimeters of scarf

Ok so let’s figure out what we know
-She knits 4 cm each night
-she needs to knit 28 centimeters

So we will you use division. 4 goes into 8,2 times.
Now 4 goes into 20,5 times.

When you add 5 plus 2 you get 7

So it will take her about 7 days to knit 28 cm

If you need to check your work which you should always do use multiplication

7 multiples by 4
Or
7+7+7+7 is 28

Which we know
28=28

So the answer is for sure 7 !!!