Faded examples · Adding and subtracting negative numbers

Non-calculator

Each example shows a little less than the one before – complete the faded steps yourself, using the same two steps every time: rewrite the double sign, then work it out. Also answer the check question.

①Example 1fully worked: read it through

Work out $5+(-3)$.

1Rewrite the double sign ($+\,-\to-$, $-\,-\to+$)

$+\,-$ becomes $-$: $5-3$

2Work it out

$=2$

Check · Why does $+(-3)$ become $-3$?

A a plus and a minus together make a minusB because $3$ is oddC you always subtractD a mistake – it stays $+3$

②Example 2fully worked: read it through

Work out $4-(-6)$.

1Rewrite the double sign ($+\,-\to-$, $-\,-\to+$)

$-\,-$ becomes $+$: $4+6$

2Work it out

$=10$

Check · Two minus signs next to each other make...

A a minusB a plusC zeroD nothing changes

③Example 3you finish the last 1 step

Work out $-2+(-5)$.

1Rewrite the double sign ($+\,-\to-$, $-\,-\to+$)

$+\,-$ becomes $-$: $-2-5$

2Work it out

$=-7$

Check · Starting at $-2$ and going $5$ MORE negative gives...

A $3$B $-7$C $7$D $-3$

④Example 4your turn: every step

Work out $-8-(-3)$.

1Rewrite the double sign ($+\,-\to-$, $-\,-\to+$)

$-\,-$ becomes $+$: $-8+3$

2Work it out

$=-5$

Check · From $-8$, adding $3$ moves you which way?

A left (more negative)B right (towards zero), to $-5$C nowhereD to $-11$

Answers · Negative Numbers

Faded examples · Adding and subtracting negative numbers

① Example 1 $+\,-$ becomes $-$: $5-3$→$=2$ $2$

Check: A: a plus and a minus together make a minus

② Example 2 $-\,-$ becomes $+$: $4+6$→$=10$ $10$

Check: B: a plus

③ Example 3 $+\,-$ becomes $-$: $-2-5$→$=-7$ $-7$

Check: B: $-7$

④ Example 4 $-\,-$ becomes $+$: $-8+3$→$=-5$ $-5$

Check: B: right (towards zero), to $-5$