GCSE Edexcel – Maths Test Questions With All Correct Answers

GCSE Edexcel – Maths Test Questions With All Correct Answers 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 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