Foundation November 2022 Paper 3 Q10
10
(a)
| When 5 is added to a negative number, the answer can be positive |
Give one example to show that this is correct. [1 mark]
(b)
| When 5 is added to a negative number, the answer can be negative |
Give one example to show that this is correct. [1 mark]
(c)
| When a number is doubled, the answer is always greater than the original number |
Give one example to show that this is not correct. [1 mark]
| Answer | Mark | Comments |
|---|---|---|
| One example that would give a positive answer | B1 | eg \(-2 + 5\;(= 3)\) or \(5 + -2\;(= 3)\) |
Additional guidance
| Evaluation is not required but if given must be correct | |
| Allow two or more correct examples eg \(-1 + 5 = 4\) and \(-4 + 5 = 1\) | B1 |
| Do not ignore an incorrect example alongside a correct example eg1 \(-1 + 5 = 4\) and \(-7 + 5 = -2\) (\(-7 + 5\) is an incorrect example) eg2 \(-1 + 5\) and \(-7 + 5\) eg3 \(-5 + 5 = 0\) and \(-2 + 5 = 3\) (\(-5 + 5\) is an incorrect example) eg4 \(-2 + 5 = 3\) and \(-4 + 5 = -9\) (−9 is an incorrect evaluation) | B0 B0 B0 B0 |
| Allow an example in words eg five added to negative four (is one) | B1 |
| The number could be −2 | B1 |
| Allow brackets around negative numbers eg \(5 + (-2)\) | B1 |
| \(5 - 2\;(= 3)\) | B1 |
| \(-5 + 5 = 0\) | B0 |
| Answer | Mark | Comments |
|---|---|---|
| One example that would give a negative answer | B1 | eg \(-6 + 5\;(= -1)\) or \(5 + -6\;(= -1)\) |
Additional guidance
| Evaluation not required but if given must be correct | |
| Allow two or more correct examples eg \(-7 + 5 = -2\) and \(-6 + 5 = -1\) | B1 |
| Do not ignore an incorrect example alongside a correct example eg1 \(-7 + 5 = -2\) and \(-1 + 5 = 4\) (\(-1 + 5\) is an incorrect example) eg2 \(-7 + 5\) and \(-1 + 5\) eg3 \(-5 + 5 = 0\) and \(-6 + 5 = -1\) (\(-5 + 5\) is an incorrect example) eg4 \(-9 + 5 = -4\) and \(-8 + 5 = -13\) (−13 is an incorrect evaluation) | B0 B0 B0 B0 |
| Allow an example in words eg five added to negative ten (is negative five) | B1 |
| The number could be −6 | B1 |
| Allow brackets around negative numbers eg \(5 + (-8)\) | B1 |
| \(5 - 6\;(= -1)\) | B1 |
| \(-5 + 5 = 0\) | B0 |
| Answer | Mark | Comments |
|---|---|---|
| One example that shows the statement is not correct | B1 | eg \(-3 \times 2\;(= -6)\) or \(2 \times -3\;(= -6)\) |
Additional guidance
| Evaluation not required but if given must be correct | |
| Allow two or more correct examples eg \(-7 \times 2 = -14\) and \(-6 \times 2 = -12\) | B1 |
| Do not ignore an incorrect example alongside a correct example eg1 \(-5 \times 2 = -10\) and \(4 \times 2 = 8\) (\(4 \times 2\) is an incorrect example) eg2 \(-4 \times 2\) and \(4 \times 2\) eg3 \(-5 \times 2 = -10\) and \(-8 \times 2 = -10\) (−10 is an incorrect evaluation) | B0 B0 B0 |
| Allow an example in words eg 0 doubled (is 0) | B1 |
| The number could be −6 | B1 |
| \(0 \times 2\) | B1 |
| \(0 + 0\) | B1 |
| \(-1 + -1\;(= -2)\) or \(-1 - 1\;(= -2)\) | B1 |
| \(-1^2 = -2\) | B0 |
| \(-1^2\) | B0 |