Number Sense Flash Cards

Distance formula

• @@\frac{{y_{2} - y_{1}}}{{x_{2} - x_{1}}}@@

• @@\frac{{(y_{2} - y_{1})^{2} + (x_{2} - x_{1})^{2}}}{{2}}@@

• @@\text{Distance} = \text{Speed} \times \text{Time}@@

• @@\text{Distance} = \text{Speed} \times \text{Time} + \text{Acceleration}@@

Area of cube given diagonal

• @@d^{2} imes 2@@

• @@rac{d^{2}}{2}@@

• @@d^{3}@@

• @@rac{d^{3}}{3}@@

elements of a set

• # letters in the set

• # numbers in the set

• # colors in the set

• # shapes in the set

Subsets

• @@2^{n}@@ where n is the number of elements

• @@n^{2}@@ where n is the number of elements

• @@2n@@ where n is the number of elements

• @@n!@@ where n is the number of elements

Median

• one in MIDDLE when put in order

• the average of all numbers

• the largest number in a set

• the smallest number in a set

1 acre

• @@\frac{1}{640}@@ square miles

• @@\frac{1}{500}@@ square miles

• @@\frac{1}{700}@@ square miles

• @@\frac{1}{800}@@ square miles

Proper subsets

• @@2^{n} - 1@@ where n is the number of elements

• @@2^{n}@@ where n is the number of elements

• @@n - 1@@ where n is the number of elements

• @@n^{2} - n@@ where n is the number of elements

Right triangle given 2 legs

• @@rac{a}{b}@@

• @@rac{a^2 + b^2}{c}@@

• @@ ext{Area} = rac{1}{2}ab@@

• @@ ext{Hypotenuse} = ext{sqrt}(a^{2} + b^{2})@@

Finding LCM of two numbers

• largest common factor × how many times factor goes into each

• smallest common multiple × how many times multiple goes into each

• greatest common divisor × how many times divisor goes into each

• sum of the two numbers × how many times each number can be divided

Volume of a cylinder

• @@r^{2} imes height imes rac{ ext{π}}{1}@@

• @@rac{1}{3} imes ext{π} imes r^{2} imes height@@

• @@2 imes ext{π} imes r imes height@@

• @@ ext{π} imes r^{2} + height@@