*In mathematics, a rate is a ratio between two measurements, often with different units.[1]. If the unit or quantity in respect of which something is changing is not specified, usually the rate is per unit time. However, a rate of change can be specified per unit time, or per unit of length or mass or another quantity. The most common type of rate is "per unit time", such as speed, heart rate and flux. Rates that have a non-time denominator include exchange rates, literacy rates and electric flux.*

When we describe the units of a rate, the word "per" is used to separate the units of the two measurements used to calculate the rate (for example a heart rate is expressed "beats per minute"). A rate defined using two numbers of the same units (such as tax rates) or counts (such as literacy rate) will result in a dimensionless quantity, which can be expressed as a percentage (for example, the global literacy rate in 1998 was 80%) or fraction or as a multiple.

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Rate is commonly used in our daily life. Here are some examples:

40 km/h - 40 kilometres per hour

30 steps/min - 30 steps in per minute

2 l/hour - 2 litres per hour

67 words/min - 60 words per 1 min

80 m/week - 80 metres per week

25km/l - 25 kilometres per 1 litre

$90/m³ - $90 per cubic metre

Think of 2 real life situations in which we use the concept of rate to describe useful information.

Here is an example:

The Singapore Flyer rotates at the rate of 0.24 m/s or 0.76 km/h

*(http://www.singaporeflyer.com/en/about-us/fun-facts-about-singapore-flyer.html)*

The website provided is not found.

ReplyDelete@Ming Yi: Uh. I think the correct link is: http://www.singaporeflyer.com/about-us/fun-facts-about-the-flyer/

ReplyDelete@Christabel: thanks :D

ReplyDeletethe speed of light = 299 792 458 m / s

ReplyDelete1. When showering, water flows out at a constant rate. Normally, water flows at a rate of 2.2 gallons of water per minute which is 8.33 liters of water per minute.

ReplyDeleteAn average walking rate is 15 minutes per mile so in one hour the average rate is 4 miles per hour.

I tweet at 50tweets/hr

ReplyDeletespeed of sound is 340.29 m / s

ReplyDeleteTerrorist kill people at 10 thousand people a year in the whole world.

ReplyDeletePeople abuse dogs at 100,000 dogs a year.

I can type 10 letters in 1s [Rate 10 letters/s]

ReplyDeleteI can say 20 words in 10s [Rate 20 words/s]

i eat 10 burgers/ hour

ReplyDelete1: the car goes by 11km/liter

ReplyDelete1.41346 usd/euro

ReplyDeletehttp://www.xe.com/ucc/

Average speed of a driver on a highway in Singapore is 80km/h

ReplyDelete1) The speed of light is 299 792 458 m / s

ReplyDelete2) The speed of sound is 340.29 m / s

The fan spins at 130 rounds per minute.

ReplyDeleteWe are now typing 3 letters per second.

http://www.singaporeflyer.com/about-us/fun-facts-about-the-flyer/

ReplyDelete100 thousand people are enter mental hospital a year.

ReplyDeletePeople (Matthew) fart 100 times a minute :D

Adam Khoo earns $0.70/second

ReplyDeleteAK 47 fires at a rate of 60 rounds/minute

1.04482 usd/aud

ReplyDeletehttp://www.xe.com/ucc/

the speed of snails is 0.013 m/s

ReplyDeleteMusic Bank shows 2 host/show :DD

ReplyDeleteMusic Core shows 4 host/show :DD

M! Countdown shows 3 host/show :DD

Inkigayo shows 4 host/show :DD

Hubble Space Telescope orbits at 17500 mph (28000 kph)

ReplyDeleteMiss Loh is giving us pop quiz at a rate of 2 pop quiz/1 month(4 weeks)

ReplyDeleteAverage walking speed is 1km/h

ReplyDeleteThe washing machine washes 30pieces of clothing in a 1h

There are about ten comments in the first minute.

ReplyDeleteThere are about five comments in the second minute.

1)I read 10 pages of my book in 20 minutes (1/2 page/min)

ReplyDelete2)I run 2.4km in 12 minutes (1/5km/min)

John can type at the rate of 5letter/sec

ReplyDeleteWe get notifications on "Facebook" at the rate of 10notifications/second

I play FT Island songs at 20 songs/h

ReplyDeleteI can type at an average rate of 20 words per minute.

ReplyDeleteStudents of class S1-02 stands up at the rate of 27.6/hr

The maximum set speed of a formula one car is 413 km/h (257mph)

ReplyDelete1. I can type at 5 letters per second.

ReplyDelete2. I can walk 30 metres per minute.