Foundation Flashcards
What are the multiples of 20?
20, 40, 60, 80, 100, 120 …
What are the factors of 20?
1, 2, 4, 5, 10, 20
How do you find 50% of a number?
÷ 2
How do you find 25% of a number?
÷ 4 (or half it and half again)
How do you find 10% of a number?
÷ 10
How do you find 1% of a number?
÷ 100
How do you find 5% of a number?
Find 10% then half it
How do you find 20% of a number?
Find 10% then double it
How do you find 75% of a number?
Add 50% and 25%
How do you ‘square’ a number?
Multiply it by itself. e.g. 5² = 5 x 5 = 25
How do you ‘cube’ a number?
Multiply it by itself and by itself again. e.g. 2³ = 2 x 2 x 2 = 8
What is the sum of the angles in a triangle?
180°
What is the sum of the angles in a quadrilateral?
360°
What is the sum of the angles in a pentagon?
540°
What is the sum of the angles in a hexagon?
720°
How do you find the area of a triangle?
½base times height
How do you find the area of a rectangle?
Length times width
How do you find the circumference of a circle?
Pi x diameter (or 2?r)
How do you find the area of a circle?
Pi x r² (?r²)
How do you find a fraction of an amount? (e.g. ¾ of 20?)
Divide by the bottom times by the top. (e.g. 20 ÷ 4 = 5, 5 x 3 = 15)
What does a cylinder look like?
tin of soup, can of pop…
What does a cone look like?
traffic cone, ice cream cone
What does a sphere look like?
ball
What does a parallelogram look like?
pushed over rectrangle
How many sides does a pentagon have?
5
How many sides does an octagon have?
8
How many sides does a hexagon have?
6
How many sides does a decagon have?
10
How many sides does a heptagon have?
7
How many sides does a nonagon have?
9
What are the first 10 square numbers?
1, 4, 9, 16, 25, 36, 49, 64, 81, 100
What are the first 10 prime numbers?
2, 3, 5, 7, 11, 13, 17, 19, 23, 29 (remember, 1 is not prime!!!)
What are the first 5 cube numbers?
1, 8, 27, 64, 125
What is a prime number?
A number divisible only by 1 and itself. e.g. 7 is a prime number as it’s factors are 1 and 7. 9 is not a prime number as it’s factors are 1 3 and 9
How do you calculate the mean?
Add up all the values and divide by how many values there are
How do you calculate the range?
Highest value subtract smallest value
How do you find the median?
Arrange all the numbers in order then find the middle value
How do you find the mode?
It is the most common value (or item)
How do you ‘square root’ a number?
Find what number multiplies by itself to give the number you are square rooting. e.g. square root 25 is 5
How do you ‘cube root’ a number? e.g. cube root of 8?
Find what number multiplies by itself and by itself again to give the number you are cube rooting. e.g. cube root of 8 is 2
How do you find the estimated mean from a frequency table?
1) Find midpoints 2) Find ‘fx column’ by multiplying midpoints by frequency. 3) Add up the ‘fx column’ and divide by total frequency
What is a radius?
A line from the centre of the circle to the circumference
What is a diameter?
A line from one side of the circle to the other passing through the centre
What is an arc?
An arc is part of the circumference
What is a tangent?
A straight line that touches a circle
What is a chord?
A line joining two points on the circle but not passing through the centre (that is the diameter)
What is a sector?
The region bound between two radii and the arc. Some people call it a ‘pizza slice.
What is a segment?
The region between a chord and an arc
What is ½ as a decimal?
0.5
What is ¼ as a decimal?
0.25
What is ¾ as a decimal?
0.75
What is 9/10 as a decimal?
0.9
What is 6/100 as a decimal?
0.06
What is 7/25 as a decimal?
0.28
What is 1/3 as a decimal?
0.33333333…..
What is ¼ as a percentage?
25%
What is ¾ as a percentage?
75%
What is ½ as a percentage?
50%
What is \u00b9\/\u2085 as a percentage?
20%
What is 0.7 as a fraction?
7/10
What is 0.13 as a fraction?
13/100
How do you convert decimals to percentages?
Multiply the decimal number by 100 and add the % symbol
How do you convert percentages to decimals?
Divide the percentage by 100
How do you convert percentages to fractions?
Write the percentage over 100 and simplify
How do you convert fractions to decimals?
Divide the numerator by denominato?
How do you convert decimals to fractions?
Remember 0.1 is one-tenth 0.01 is one-hundredth etc. e.g. Write 0.7 as a fraction. As this is seven-tenths it would be 7/10?
How do you convert fractions to percentages?
Method 1) Find an equivalent fraction with 100 on the demoninator. The numerator is the percentage. Method 2) Divide numerator by denominator to find the decimal. Then multiply by 100
How do you multiply fractions?
Multiply numerators and multiply denominators. Simplify if you can
How do you divide by a fraction?
Multiply by the reciprocal of the second fraction, i.e : flip the second fraction, change the divide into a times
How do you add fractions?
Make both fractions have a common denominator then add
What is a reciprocal?
You find a reciprocal by flipping over a fraction. A number multiplied by it’s reciprocal is 1
What is a negative X a negative?
Positive. e.g. -4 x -2 = 8