Question

2 3/5 - 1 3/8 estimate

Answer 1

1 9/40

first you make the denominated 40

Then you multiply the same number you used to multiply the denominator

Then subtract

Answer 2

2 3/5 - 1 3/8
estimate : 3 - 1 = 2

actual :
2 3/5 - 1 3/8 =
13/5 - 11/8 =
104/40 - 55/40 =
49/40 = 1 9/40