(a)[1]
The mass of a bag of almonds is $125\text{ g}$ when rounded to the nearest gram. Write down the lower bound for the mass of the bag of almonds.
(b)[2]
The mass of a large box is $500\text{ g}$, correct to the nearest $10$ grams. The mass of a small box is $250\text{ g}$, correct to the nearest $10$ grams. Calculate the upper bound for the difference between the mass of a large box and the mass of a small box.