LO Adding and subtracting with RAG negative numbers
LO Adding and subtracting with RAG negative numbers Key Words: Positive, Minus 16 -Dec-21 Look at the set of questions on the starter activity sheet. Attempt to answer all of them. Don’t worry if you’re not sure if your answers are correct. You will get the opportunity to change your answers at the end of the lesson. You can use the number line to help you.
Keep a record of your answers, you may want to change them at the end of the lesson. Mini whiteboards ready – one between two, you and your partner must come to an agreed answer.
Why is this ‘ 4’? 4
How much is this?
Making 3 Show me another way of making 3. Can you do one using 11 charges altogether?
How much is this?
How much is this? – 2
How much is this?
How much is this? 0
How much is this?
How much is this? +3
How would you describe what happens here?
How would you describe what happens here?
How would you describe what happens here? (+4) +
How would you describe what happens here? (+4) + (-2) =
How would you describe what happens here? (+4) + (-2) = +2
Task A 1. Match each diagram with one of the calculations, write the calculation in the space beneath the diagram. 2. Write the answer to the calculation after the equals sign. 3. Check that the answer matches what you see in the drawing. (+5) – (+2) = (+5) + (-2) = (-5) – (-2) = (-5) + (+2) =
Task B Draw diagrams to represent the following calculations. (-2) + (-4) = (+ 4) + (-5) = (+ 7) + (-3) = (+8) - (+ 3) = (-8) + (- 3) = (-6) + (+3) =
Task B Now draw diagrams to represent your own calculations.
What about this? +2
What about this? What do we get when we take away a negative?
What about this? (+2) -
What about this? (+2) – (– 1) =
What about this? (+2) – (– 1) = (+3)
Another example
Another example +1
Another example (+1) – (– 2)
Another example (+1) – (– 2) = +3
How can I draw (+2) – (+5)?
How can I draw (+2) – (+5)? Another way of thinking of (+2)…
How can I draw (+2) – (+5)? And another. . .
How can I draw (+2) – (+5)? And another. . . Do you agree that this is still (+2)?
How can I draw (+2) – (+5)? How can I take away (+5)?
How can I draw (+2) – (+5)? (+2) – (+5) =
How can I draw (+2) – (+5)? (+2) – (+5) = (-3)
Task C 1. Match each diagram with one of the calculations, write the calculation in the space beneath the diagram. 2. Write the answer to the calculation after the equals sign. 3. Check that the answer matches what you see in the drawing. (+2) - (+5) = (-2) - (-5) = (+5) - (-2) = (-2) - (+5) = (+2) - (-5) = (+2) - (+5) =
Extension Task Split your page into three columns, like below. For each statement decide if the statement is sometimes true, always true or never true. You must give reasons for your answers. Always True Sometimes True Never True
Answers (1)
Calculations (2)
Look back at your answers for the starter activity. Do you want to change any of your answers?
Using a number line (+8) – (+3)=
Using a number line (– 3) + (+8)=
Using a number line (+8) – (– 3)=
Using a number line (– 8) + (– 3)=
Using a number line (+3) – (+8)=
Using a number line (– 8) – (– 3)=
- Slides: 54
