For the first one, you would use a number line to determine this. His starting point is zero. You would draw a line to to 14.6, then subtract 14.6 minus 9.8 which is 4.8. Draw another line to 4.8. Finally, add 5.3 to 4.8. What do you have?
Second one: remember the P.E.M.D.A.S strategy.
Add the numbers 6.89 and 14.52, which is 21.41. Finally combine that with the negative number 14.52. Combing a positive with a negative is basically subtraction, so you have 6.89. Hope I helped.
