Negative numbers for the 11 plus

Below zero, the number line keeps going. Minus fourteen is further down than minus three, so minus fourteen is less. And a gap that crosses zero is really two gaps: the bit below, and the bit above.

From minus fourteen up to zero is fourteen. From zero up to twenty-one is twenty-one. Add the two gaps: fourteen plus twenty-one. Thirty-five degrees.

The trap is twenty-one take away fourteen, which gives seven. That treats the minus fourteen as if it were above zero and ignores the zero in the middle.

Part of the Number & Place Value topics for the 11+.

• 1.1Reading and writing large numbersOne zero can change everything
• 1.2Rounding numbersLook one digit to the right
• 1.3Comparing and orderingThe first difference decides it
• 1.4Roman numeralsSmall before big means take away
• 1.6Prime numbers, factors and multiplesShared factors make it smaller
• 1.7Square and cube numbersA root is not a half
• 1.8Prime factorisationSplit until every end is prime

Every 11 plus maths topic