click below
click below
Normal Size Small Size show me how
Year 8 maths
Frfactions,mixed numbers,decimals, percentages, areas, colume, sig figs and more
Question | Answer |
---|---|
How do you make a fraction into a decimal? | Divide The numerator by the denominator |
How do you make a decimal into a fraction? | Put it over the number of place values after the decimal point, simplify fraction if necessary. |
How do you add and subtract fractions? | Make a common denominator then add/subtract |
How do you multiply Fractions? | Multiply the numerators together, followed by the denominator. |
How do you divide Fractions? | Turn the 2nd fraction then time. |
How do you add mixed numbers? | Add together the mixed numbers, then make a common denominator and add together the fractions. Then add together the whole number and the fraction |
How do you Subtract mixed numbers? | First subtract the second whole number by the first, then subtract the second fraction by the first. |
How do you multiply mixed numbers? | Write as an improper fraction then times. |
How do you divide mixed numbers? | Write as an improper fraction, swap round the 2nd fraction and times. |
Mixed numbers into improper fractions? | Times the whole number by the denominator then add the numerator. |
Multiplying decimal numbers? | Make the decimal a whole number, then times. But because you timed the decimal you need to undo the operation by dividing the answer by 10, 100, 1000 etc. |
How do you add and subtract decimals? | Line up the decimals under each other then add/subtract. |
Expressing 1 quantity as a percentage as another? | Place the two numbers over each other as a fraction and times by 100, turn into a mixed fraction then a percentage. |
Making a fraction into a percentage? | Change into decimal than percetage. |
How do you multiply a single bracket? | Everything inside the bracket must be multiplied by the number or term outside the bracket. |
What is pi? | 3.1415926 (Area of a circle) Pi, r squared. |
Directed numbers rules? | + + = +- - = +- + = -+ - = - |
What is a perimeter? | All the sides ADDED together |
How do you simplify expression with brackets? | BIDMAS |
Area of a triangle? | 1/2 Base x height |
Area of a square? | Length of side Squared |
Area of a rectangle? | Breadth x Height |
Area of a Parrallelogram? | Breadth x Height |
Area of a Trapezoid? | Length of the top side + The base divided by 2 timed by Vertical height |
Area of a circle? | Pi r squared |
Volume of a cuboid? | Height × Width × Length |
Volume of a cube? | Height x width x length |
Volume of cylinder? | Find the area of thr circle than times it by the height. |
Volume of a prism? | Area if cross section x length |
How do you Round? | Identify the posistion of the last digit, look at the digit to the right. If the decider is 5 or more you round up if the decider is 4 or less you leave the digit as it is. |
What is a significant figure? | Sig fig approach from the left and start counting as soon as you meet the non zero figure. Once you have started counting any figure including zero is significant. |
What do the angles in a triangle add up to? | 180 degrees |
What do angles around a point equal up to? | 360 degrees |
What do angles on a line add up to? | 180 degrees |
What is a isosceles triangle? | A triangle with two equal sides |
What is a equilateral triangle? | Triangle where all the sides are equal, adding up to 60 degrees. |
What is a interior and exterior angle? | On a triangle the exterior angle is the sum of two interior angles. If you add up the interior angle and exterior angle you get a straight line, 180 degrees. The exterior is on the outer side of the shape and the interior is on the inside. |
What does BIDMAS stand for? | B - BracketsI - Indices (Powers)D - DivisionM - MultiplicationA - AddingS - subtracting |
What are the first 12 prime numbers? | 2,3,5,7,11,13,17,19,23,29,31,37(Hint - All end in 1,3,7,9) |
What are HCF & LCM? | We can break a number into a product of itsw primes.HCF - Highest common Factor that can both be divided into without a remainder.LCM - Lowest common multiple, the lowest number they can both be divided into. |
What are the multiplication and division laws for indices? | Multiplication - Am x An - Am+nDivision - Am / An = A m-n |
What is standard form? | A number is written as A x 10n, A is always between 1 and 10. n tells us how many place to move |
What is an acute angle? | Angle less than 90 degrees |
What is and obtuse angle? | Angles between 90 and 180 degrees. |
What is a reflex angle? | Angles between 180 and 360 degrees. |
What are the first 15 square numbers? | 1,4,9,16,25,36,49,64,81,100,121,144,169,196,225. |
What is a square root? | The opposite of a square number. |
What is a cubed number? | Times a number by itself three times |
What is a cubed root? | The opposite of a cube number. |
What is the equivilents to 1km in m? | 1000m |
1m in cm? | 100cm |
1cm in mm? | 10mm |
1kg in g? | 1000g |
1 Tonne in kg? | 1000kg |
1g in mg? | 1000mg |
1 Litre in ml | 1000ml |