You work this math problem like this:
.50
-1.25
_____
- .75
25
475
875
1/4 tsp
125
One-half times three gives three halves (3/2), which is the same as one and one-half.
-125
0.8
The number half-way between 125 and 150 is (125 + 250) / 2 = 187.5.
minus one half
1.25
Yes, half of 250 is 125. To prove it: use a calculator and calculate 125 times 2.