upper and lower bound

A rectangular field has a length of 9 m and a width of 11 m.

Length are measured to the nearest metre.

What is the greatest possible area of the field?

A metal rod has a length of 2 cm to the nearest cm.

What is the greatest possible length of the rod?

A rectangular field has a length of 10 m and a width of 11 m. Length are measured to the nearest metre.

What is the greatest possible area of the field?

A cuboid measures 5 x 4 x 19 m measured to the nearest metre.

What is the least possible volume of the cuboid?

A cuboid measures 11 x 13 x 7 m measured to the nearest metre. What is the greatest possible volume of the cuboid?

The volume of oil in a tank is 1000 litres, correct to the nearest 10 litres.

The oil is poured into tins of volume 2.5 litres, correct to one decimal place.

Calculate the upper bound of the number of tins which will be required.

In a race, Paula runs 25 laps of a track.

Each lap of the track is 400 m, correct to the nearest metre.

Paula’s average speed is 5.0 m/s, correct to one decimal place. Calculate the upper bound for the time that Paula takes to run the race. Give your answer in minutes and seconds, correct to the nearest second

A metal cube has sides of length 4.5cm, correct to the nearest 0.5cm. The cube is melted down and the metal is used to make small spheres. Each sphere has a radius of 3mm, correct to the nearest millimetre. Work out the greatest number of spheres that could be made from the metal.