Slides in this set
Direct proportion= when 2 quantities increase and
decrease in the same ratio.
Inverse proportion= when one quantity increases
at the same rate as the other quantity decreases.…read more
Converting a recurring decimal to
1. let x equal the recurring decimal
2. multiply both sides of this equation by 10 if 1 digit recurs, 100 if 2
digits recur and so on.
3 .Subtract the original equation from the new equation
4. Rearrange x as a fraction
E.g. x= 0.234234234...
234/999 = 0.234234...…read more
Upper and lower bounds
Upper bound of a number= the highest value that rounds down to that number
Lower bound of a number= the lowest value which rounds up to that number
Calculating the bounds of s=x+y
Upper bound of s upper bound of x+ upper bound of y
Lower bound of s- lower bound of x+ lower bound of y.
calculating the bounds of d=x-y
Upper bound of d= upper bound of x- lower bound of y
Lower bound of d= lower bound of x- upper bound of y
Calculating the bounds of p=xy
Upper bound of p=upper bound of x multiplied by the upper bound of y
Lower bound of p=lower bound of x multiplied by the lower bound of y
Calculating the bounds of q=x/y
Upper bound of q= upper bound of x divided by the lower bound of y
Lower bound of q= lower bound of x divided by the upper bound of y…read more
Compound interest= interest paid on the total amount including previous interest
Amount after n years= original amount x multiplier
Increasing an amount by a percentage= work out the original amount and add it to the
Decreasing an amount by a percentage- work out the percentage of the amount and
subtract it from the original number
Writing one quantity as a percentage of another quantity- write the first quantity as a
fraction of the 2nd quantity and then covert the fraction as a percentage
Finding the percentage profit or loss= use the formula
Percentage Profit/loss = profit/loss/original amount x 100%…read more
Solving Linear equations
Apply operations to both sides of the equation
until the unknown is on its own on one side of
the equation only.
You must- collect like terms and follow the rules
of bidmas and eliminate fractions by multiplying
each term by the lcm of the denominators.
Solutions can be whole numbers, fractions,
decimals and negative numbers…read more