Easy mathz of f.2 plz help quick

1) The area of a residential flat is 50m2 (corr. to the nearest m2)
maximun absolute error
= 1/2×correct to the nearest
= 1/2×1 m2
= 0.5m2
percentage error
= maximun absoulte error / measured value×100%
= 0.5/50×100%
= 1%

2)The monthly salary is $25000 (corr. to the nearest integer)
maximun absolute error
= 1/2×1 m2
= 0.5m2
percentage error
= 0.5/25000×100%
= 0.002%

3)The diagonal of porcelain tile is 14cm (corr. to 2 sig fig)
maximun absolute error
= 1/2×1 cm
= 0.5cm
percentage error
= 0.5/14×100%
= 3.57%

4)The length of a piece of cloth is 280cm (corr.to 3 sig.fg)
maximun absolute error
= 1/2×1 cm
= 0.5cm
percentage error
= 0.5/280×100%
= 0.18%

5)The weight of a hen is 1.5 kg (corr.to the nearest 0.1 kg)
maximun absolute error
= 1/2×0.1 cm
= 0.05cm
percentage error
= 0.05/1.5×100%
= 3.33%

6)Our local population is 6.4 mllons (corr. to the nearest 0.5 million)
maximun absolute error
= 1/2×0.5 cm
= 0.25cm
percentage error
= 0.25/6.5×100%
= 3.85%