When you use place value to exchange equal amounts when renaming a number, what are you doing

Abby is preparing fruit punch for her party. she starts with a bowl filled with liquid that has 1/2 fruit juice and 1/2 sprite, but she decides it's too fruity. so she pours out 1/4 of the liquid, and then fills the bowl up again with sprite. what fraction of the punch is now sprite?

Landon wrote that 3−2.6=4. which statement about his answer is true?

What number line represents the solution set for the inequality -1/2 greater than or equal to 4