Maths

• When estimating, to how many significant figures should numbers be rounded?

  One
• What is 6.32 rounded to one significant figure?

  6
• What is 6.51 rounded to one significant figure?

  7
• What is 0.503 rounded to one significant figure?

  0.5
• After rounding to one significant figure, what is 6 times 7?

  42
• What operation effectively occurs when dividing by 0.5?

  Doubling
• What is 42 divided by 0.5?

  84
• What should you do when you see the word "estimate" in a math problem?

  Round to one significant figure
• In prime factorization, what form should the final answer be in?

  Index form
• In a prime factor tree, what kind of numbers should be locked off?

  Prime
• What are the prime factors of 180?

  2, 3, 5
• Express 180 as a product of its prime factors.

  $2 \times 2 \times 3 \times 3 \times 5$
• Express 180 as a product of prime factors in index form.

  $2^2 \times 3^2 \times 5$
• What does LCM stand for?

  Lowest Common Multiple
• What is the lowest common multiple of 15 and 40?

  120
• If there are 15 pencils in a pack and 40 pens in a box, how many packs of pencils are needed to have the same amount as three boxes of pens?

  8
• If there are 15 pencils in a pack and 40 pens in a box, how many boxes of pens are needed to have the same amount as eight packs of pencils?


  3
• What does HCF stand for?

  Highest Common Factor
• What is the highest common factor of 72 and 90?

  18
• When finding the HCF using the prime factor method, what should you look for?

  Common prime factors
• In an inequality represented on a number line, what does a colored-in circle indicate?

  The value is included
• On a number line, how should $-2 \le x < 4$ be represented?


  Colored circle at -2, open at 4
• In the inequality $x \ge 1$, what does the symbol $\ge$ mean?


  Greater than or equal to
• How is $x \ge 1$ represented on a number line?


  Colored circle at 1, arrow right
• What is 10% of 640?

  64
• What is 20% of 640?

  128
• What is 640 plus 20%?

  768
• What is 768 minus 68?

  700
• What is the most important percentage to know for calculations?

  10%
• What is 700 divided by 10?


  70
• What is a reverse percentage question?

  Working out a past price
• If a mobile phone is reduced by 20% and the sale price is £500, what percentage does £500 represent?

  80%
• If £500 equals 80%, what is 1%?

  £6.25
• If a mobile phone is reduced by 20% and the sale price is £500, what was the original price?

  £625
• If 80% corresponds to £500, what division gives 10%?

  500 / 8
• What is 500 divided by 8?

  62.5
• If a house rises in value by 3% and the value increases by £7500, what percentage does £7500 represent?

  3%
• If £7500 equals 3%, what is 1%?

  £2500
• If a house rises in value by 3% and the value increases by £7500, what was the original value of the house?

  £250,000
• What does "per annum" mean?

  Per year