The scarf that anita is knitting is 12/1-4 inches long. the scarf that jeff is knitting is 4 times as long. how long is jeff’s scarf?

If you meant 12 1/4 inches long then your 4 feet and 1 inch long or 49 inches.

12 1/4 times 4 is the length of Jeff's scarf.
Convert 12 1/4 to an improper fraction by multiplying 12 by 4 and adding 1.
12(4) = 48 + 1 = 49. Add previous fraction denominator. 49/4

49/4 × 4/1 =?
Multiply across:
49 × 4 = 196 and 4 × 1 = 4
196/4 
Simplify:
Let's see if 196 can be divided by 4to get a whole number:
196 ÷ 4 = 49

Jeff's scarf is approximately 49 inches long.

The difference is 5,100m?