# Math and Arithmetic

## Math is the study of abstractions. Math allows us to isolate one or a few features such as the number, shape or direction of some kind of object. Then we can study what can be learned about the behavior of those features while ignoring everything else about the object.

### What is 20 degrees Celsius in Fahrenheit?

20°C is equal to 68°F
The conversion formula is °F = (9/5 °C)+ 32
-------------------------------
F = [20 * (9/5)] + 32
F = 36 + 32
F = 68.
It's easy to convert from Celsius to Fahrenheit by yourself. Tf =
(9/5)*Tc+32, where Tc = temperature in degrees Celsius, Tf =
temperature in degrees Fahrenheit.20 C is 68 F.
20 degrees Celsius is 68 degrees Fahrenheit.
Conversion from Celsius to Fahrenheit is done in three steps:
1. Multiply value in degrees Celsius by 9.
2. Divide result of step 1 by 5.
3. Add 32 to result of step 2.
Conversion formula: [°F] = [°C] * 9 / 5 + 32 = 20 * 9 / 5 + 32 =
68 °F
68 F

### How many different ways can you make 23 cents in change?

Assuming you're American:
23¢ = 23 × 1¢
= 18 × 1¢ + 5¢
= 13 × 1¢ + 2 × 5¢
= 13 × 1¢ + 1 × 10¢
= 8 × 1¢ + 3 × 5¢
= 8 × 1¢ + 1 × 5¢ + 1 × 10¢
= 3 × 1¢ + 4 × 5¢
= 3 × 1¢ + 2 × 5¢ + 1 × 10¢
= 3 × 1¢ + 2 × 10¢
So there are 9 different ways.
If you were European, there would also be a 2 cent coin and a 20
cent coin to consider in the mix.

### How long will it take you to drive 86 miles drving at the speed of 65?

For questions like this, it's is very helpful to look at units
when you're doing your calculations.
you're traveling at 65 miles/hour which also means that in 1
hour you travel 65 miles (1hour/65miles). So you have
1 hour / 65 miles * 86 miles = (1 hour * 86 miles ) / (65 miles)
= 86/65 hours = 1.323 or approximately 80 minutes.

### What is bigger - a pint or a quart?

One US quart is equal to two US pints each comprising 16 fluid
ounces.
One Imperial quart is equal to two Imperial pints each
comprising 20 fluid ounces.
In each standard of measurement:
one quart is equal to one quarter of a gallon
and
4 quarts equal one gallon.
I learned this visual method in school. Draw a big "G" to
represent gallons. Inside the "G" draw 4 "Q"s. "Q"=Quart. Inside
each "Q" draw 2 "P"s. "P"=Pint. Inside each "P" draw 2 "C"s. "C"
=Cup.
So if you need to know which is bigger you now have a visual
representation.