It depends on where you are in the world as to what the correct answer is. If you are in the US, 1 Gallon is equal to 128 fluid ounces. But in the UK 1 Gallon is equal to 160 fluid ounces. There are many ways to find out these answers, the internet being the quickest and most reliable source. There are plenty of conversion charts on the web which are extremely easy to use, but be careful to choose the correct country as the US differs slightly from other countries. For example, the US fluid ounce is about 4 per cent larger than the UK fluid ounce, hence the answer to this question differs. If you cannot get to a laptop or computer then an encyclopaedia or a library would give you the answers. Gallons, quarts, pints and fluid ounces are all the old Imperial system of fluid measurement. This system was used for centuries in Britain, the Commonwealth and the USA. A new system was founded in France in the 18th Century. Before scales were invented people used to measure in cups and spoonfuls. Some old cook books will still use cups and spoonfuls for recipes especially in the US. For example, 1 cup = 8 fluid ounces or 16 tablespoons, which in Metric is 237 millilitres.
When Metric came into force some folk found it extremely difficult to adjust even though children have been taught in schools since the 70's, but old habits die hard and people continued to use the Imperial measurements and still do to this day. You can still find Imperial measurement in supermarkets usually showing the Metric weight with the Imperial weight in brackets. Most people in the UK and the US still use pounds and ounces and feet and inches.
Here are a few websites that will help you convert Imperial to Metric.
www.csgnetwork.com/cookmeasuretable2.html
www.metric-conversions.org/measurement-conversions.htm
When Metric came into force some folk found it extremely difficult to adjust even though children have been taught in schools since the 70's, but old habits die hard and people continued to use the Imperial measurements and still do to this day. You can still find Imperial measurement in supermarkets usually showing the Metric weight with the Imperial weight in brackets. Most people in the UK and the US still use pounds and ounces and feet and inches.
Here are a few websites that will help you convert Imperial to Metric.
www.csgnetwork.com/cookmeasuretable2.html
www.metric-conversions.org/measurement-conversions.htm