What is the length of a ruler in metres if it is 100 centimetres long?

There are 100 centimetres in 1 metre.

To convert 100 centimetres to metres, divide by 100.

The length of the ruler in metres is $\boxed{\text{1 m}}$.

There are 1000 kilograms in 1 tonne.

Total mass = $2000 \text{ kg} + 300 \text{ kg}$

The total mass of the container in kilograms is $\boxed{\text{2300 kg}}$.

There are 1000 millilitres in 1 litre.

There are 7 days in a week.
Weekly production = Daily production in mL $\times$ 7 days

The factory will produce $\boxed{\text{2415000 mL}}$ of oil in one week.

There are 1000 grams in 1 kilogram.

To convert grams to kilograms, divide by 1000.

The mass of the maize sack in kilograms is $\boxed{\text{18.25 kg}}$.

Recall that $1 \text{ L} = 1000 \text{ mL}$.

First cow's production:

Total for first cow = $2000 \text{ mL} + 353 \text{ mL} = 2353 \text{ mL}$

Second cow's production:

Total for second cow = $5000 \text{ mL} + 452 \text{ mL} = 5452 \text{ mL}$

Total volume = $2353 \text{ mL} + 5452 \text{ mL}$

Alternatively, we can add litres and millilitres separately:
Total litres = $2 \text{ L} + 5 \text{ L} = 7 \text{ L}$
Total millilitres = $353 \text{ mL} + 452 \text{ mL} = 805 \text{ mL}$
Total volume = $7 \text{ L } 805 \text{ mL}$

The total volume of milk produced by the two cows is $\boxed{\text{7805 mL or 7 L 805 mL}}$.

Recall the conversion factors:
$1 \text{ kg} = 1000 \text{ g}$
$1 \text{ tonne} = 1000 \text{ kg}$
$1 \text{ g} = 1000 \text{ mg}$ (so $1 \text{ kg} = 1000 \times 1000 \text{ mg} = 1000000 \text{ mg}$)

• 7500 grams (g) to kilograms (kg):

  $$7500 \text{ g} \times \frac{1 \text{ kg}}{1000 \text{ g}} = 7.5 \text{ kg}$$

• 3 tonnes to kilograms (kg):

  $$3 \text{ tonnes} \times \frac{1000 \text{ kg}}{1 \text{ tonne}} = 3000 \text{ kg}$$

• 4000 kilograms (kg): This is already in kilograms.

  $$4000 \text{ kg}$$

• 2350 milligrams (mg) to kilograms (kg):

  $$2350 \text{ mg} \times \frac{1 \text{ g}}{1000 \text{ mg}} \times \frac{1 \text{ kg}}{1000 \text{ g}} = \frac{2350}{1000000} \text{ kg} = 0.00235 \text{ kg}$$

We have:
$7.5 \text{ kg}$
$3000 \text{ kg}$
$4000 \text{ kg}$
$0.00235 \text{ kg}$

Comparing these values, $4000 \text{ kg}$ is the largest.

The largest measurement is $\boxed{\text{4000 kilograms}}$.
Reason: When all measurements are converted to a common unit (kilograms), 4000 kg is the largest value ($7.5 \text{ kg}$, $3000 \text{ kg}$, $4000 \text{ kg}$, $0.00235 \text{ kg}$).

Recall that $1 \text{ L} = 1000 \text{ mL}$.
Total bucket volume = $10 \text{ L} = 10 \times 1000 \text{ mL} = 10000 \text{ mL}$

Water needed = Total bucket volume - Water added

$\boxed{\text{4466 mL}}$ of water are needed to fill the bucket.

All masses are already in grams, so we can add them directly.
Total mass = Mass of flour + Mass of rice + Mass of salt

The total mass of the products purchased is $\boxed{\text{209320 g}}$.