GCSE EDEXCEL MATHS ACTUAL EXAM WITH QUESTIONS AND CORRECT VERIFIED
ANSWERS GRADED A+ GUARANTEED PASS
Finding the LCM of two numbers when you have the prime factors - (answer)- List all the prime factors
out
- If a factor appears more than once, list it that many times, e.g. 2, 2, 2, 3, 4 and 2, 2, 3, 4 would be 2, 2,
2, 3, 4
- Multiply these together to get the LCM
Finding the HCF of two numbers when you have the prime factors - (answer)- List all the prime factors
that appear in both numbers
- Multiply these together
Multiplying fractions - (answer)Multiply the top and bottom separately
Dividing fractions - (answer)Turn the second fraction upside down then multiply
Rule for terminating and recurring decimals - (answer)If the denominator has prime factors of only 2 or
5, it is a terminal decimal
Turning a recurring decimal into a fraction - (answer)- Name the decimal with an algebraic letter
- Multiply by a power of ten to get the one loop of repeated numbers past the decimal point
- Subtract the larger value from the single value to get an integer
- Rearrange
- *Simplify*
Turning a recurring fraction into a decimal when the recurring decimal is not immediately after the
decimal, e.g. r = 0.16666... - (answer)- Name the decimal with an algebraic letter e.g. r = 0.16666...
- Multiply by a power of ten to get the non-repeating part out of the bracket e.g. 10r = 1.6666...
- Multiply to get the repeating part out of the bracket e.g. 100r = 16.6666...
- Take away the larger value from the smaller one (to get an integer) e.g. 100r - 10r = 90r = 15
,GCSE EDEXCEL MATHS ACTUAL EXAM WITH QUESTIONS AND CORRECT VERIFIED
ANSWERS GRADED A+ GUARANTEED PASS
r = 15/90
- *Simplify* e.g. 15/90 = 1/6
Turning a fraction into a decimal - (answer)- Make the fraction have all nines at the bottom
- The number on the top is the recurring part, the number of nines is the number of recurring decimals
there are
Significant figures - (answer)The first number which isn't a zero. This is rounded.
Rules for calculating with significant digits - (answer)
Estimating square roots - (answer)- Find two numbers either side of the number in the root
- Make a sensible estimate depending on which one it is closer to
Truncated units - (answer)When a measurement is truncated, the actual measurement can be up to a
whole unit bigger but no smaller, e.g. 2.4 truncated to 1 d.p. is 2.4 ≤ x < 2.5
Multiplying and dividing standard form - (answer)- Convert both numbers to standard form
- Separate the power of ten and the other number
- Do each calculation separately
Adding and subtracting standard form - (answer)- Convert both numbers into standard form
- Make both powers of 10 the same in each bracket
- Add the two numbers and multiply by whatever power of ten; they are to the same power so this can
be done
Negative powers - (answer)1 over whatever the number to the power was, e.g.
, GCSE EDEXCEL MATHS ACTUAL EXAM WITH QUESTIONS AND CORRECT VERIFIED
ANSWERS GRADED A+ GUARANTEED PASS
7⁻² = ² =
a⁻⁴ = 1 / a⁴
If the number is a fraction, then it is swapped around, e.g.
(3/5)⁻² = (5/3)² =
Fractional powers - (answer)Something to the power of 1/2 means square root
Something to the power of 1/3 means cube root
Something to the power of 1/4 means fourth root, e.g.
25^½ = √25 = 5
Two-stage fractional powers - (answer)When there is a fraction with a numerator higher than one, spilt
it into a fraction and a power and do the root first, then power, e.g.
64^5/6 = (64^1/6)⁵ = (2)⁵ = 32
Difference between two squares - (answer)a²-b²=(a+b)(a-b)
Simplifying surds - (answer)Split the number in the root into a square number and the lowest other
number possible, e.g.
√250 = √(25 × 10) = 5√10
Rationalising the denominator - (answer)This is done to get rid of a surd on the denominator. You
multiply by the same fraction of the surd, but with the operation the other way round.
ANSWERS GRADED A+ GUARANTEED PASS
Finding the LCM of two numbers when you have the prime factors - (answer)- List all the prime factors
out
- If a factor appears more than once, list it that many times, e.g. 2, 2, 2, 3, 4 and 2, 2, 3, 4 would be 2, 2,
2, 3, 4
- Multiply these together to get the LCM
Finding the HCF of two numbers when you have the prime factors - (answer)- List all the prime factors
that appear in both numbers
- Multiply these together
Multiplying fractions - (answer)Multiply the top and bottom separately
Dividing fractions - (answer)Turn the second fraction upside down then multiply
Rule for terminating and recurring decimals - (answer)If the denominator has prime factors of only 2 or
5, it is a terminal decimal
Turning a recurring decimal into a fraction - (answer)- Name the decimal with an algebraic letter
- Multiply by a power of ten to get the one loop of repeated numbers past the decimal point
- Subtract the larger value from the single value to get an integer
- Rearrange
- *Simplify*
Turning a recurring fraction into a decimal when the recurring decimal is not immediately after the
decimal, e.g. r = 0.16666... - (answer)- Name the decimal with an algebraic letter e.g. r = 0.16666...
- Multiply by a power of ten to get the non-repeating part out of the bracket e.g. 10r = 1.6666...
- Multiply to get the repeating part out of the bracket e.g. 100r = 16.6666...
- Take away the larger value from the smaller one (to get an integer) e.g. 100r - 10r = 90r = 15
,GCSE EDEXCEL MATHS ACTUAL EXAM WITH QUESTIONS AND CORRECT VERIFIED
ANSWERS GRADED A+ GUARANTEED PASS
r = 15/90
- *Simplify* e.g. 15/90 = 1/6
Turning a fraction into a decimal - (answer)- Make the fraction have all nines at the bottom
- The number on the top is the recurring part, the number of nines is the number of recurring decimals
there are
Significant figures - (answer)The first number which isn't a zero. This is rounded.
Rules for calculating with significant digits - (answer)
Estimating square roots - (answer)- Find two numbers either side of the number in the root
- Make a sensible estimate depending on which one it is closer to
Truncated units - (answer)When a measurement is truncated, the actual measurement can be up to a
whole unit bigger but no smaller, e.g. 2.4 truncated to 1 d.p. is 2.4 ≤ x < 2.5
Multiplying and dividing standard form - (answer)- Convert both numbers to standard form
- Separate the power of ten and the other number
- Do each calculation separately
Adding and subtracting standard form - (answer)- Convert both numbers into standard form
- Make both powers of 10 the same in each bracket
- Add the two numbers and multiply by whatever power of ten; they are to the same power so this can
be done
Negative powers - (answer)1 over whatever the number to the power was, e.g.
, GCSE EDEXCEL MATHS ACTUAL EXAM WITH QUESTIONS AND CORRECT VERIFIED
ANSWERS GRADED A+ GUARANTEED PASS
7⁻² = ² =
a⁻⁴ = 1 / a⁴
If the number is a fraction, then it is swapped around, e.g.
(3/5)⁻² = (5/3)² =
Fractional powers - (answer)Something to the power of 1/2 means square root
Something to the power of 1/3 means cube root
Something to the power of 1/4 means fourth root, e.g.
25^½ = √25 = 5
Two-stage fractional powers - (answer)When there is a fraction with a numerator higher than one, spilt
it into a fraction and a power and do the root first, then power, e.g.
64^5/6 = (64^1/6)⁵ = (2)⁵ = 32
Difference between two squares - (answer)a²-b²=(a+b)(a-b)
Simplifying surds - (answer)Split the number in the root into a square number and the lowest other
number possible, e.g.
√250 = √(25 × 10) = 5√10
Rationalising the denominator - (answer)This is done to get rid of a surd on the denominator. You
multiply by the same fraction of the surd, but with the operation the other way round.
