Integers with Manipulatives
Numberlines – Integers (+, -) Adding –Forward direction (direction you are facing) -2 + 3 = 1 + 2 = -3 + 1 = 1 2 3 4 -1 -2 -3 -4 1 3 -2
Numberlines – Integers (+, -) Subtracting – change direction 2 - 3 = -1 - 2 = -1 - - 2 = 2 - + 1 = 1 2 3 4 -1 -2 -3 -4 -1 + -3 +1 - + 1
Integer Chips / Tiles Negative - Positive +
The collections shown here are “zero pairs”. Zero pairs have a value of zero.
What is the value? Has a value of +5. Has a value of +5. Has a value of +5. Has a value of +5. Build a different collection that has a value of +5.
ADDING INTEGERS with Tiles
Build your initial collection, add your other collection, then find the value of the collection. 5 + (+3) = +8
Build your initial collection, add your other collection, then find the value of the collection. zero pairs 5 + (-3) = 2
SUBTRACTING INTEGERS with Tiles
Subtracting - take away Example 1: 9 – 3 = 6 Build your initial collection, then take away the other collection (if you need to add a collection of zero pairs in order to take away then add them), then find the value of the collection take away
Subtracting - take away Example 2: –8 – (–2) = –6 take away Build your initial collection, then take away the other collection (if you need to add a collection of zero pairs in order to take away then add them), then find the value of the collection
Subtracting - take away method Example 3: –8 – (+2) = –10 Build your initial collection, then take away the other collection (if you need to add a collection of zero pairs in order to take away then add them), then find the value of the collection take away
Adding, Subtracting Integers 0 - +3 = 0 - 3 = 1 + -2 = 1 - 2 = -3 - - 5 = -3 + 5 = -3 -1 2
Model MULTIPLYING INTEGERS
3 × 4 3 groups of 4 + 3 × 4 = 12
3 × (–2) 3 groups of –2 + 3 × (–2) = –6
take away 2 groups of positive 3 If multiplying by a positive add groups, what does it mean to multiply by a negative? Subtract groups! Example: –2 × 3 take away 2 groups of positive 3 So you need a collection to subtract from, so build a collection of zero pairs
= –6 –2 × 3 Take away 2 groups of 3 Example: Have to build a collection of zero pairs = –6
Example 2 (–4) × (–2) = 8
Write as a Multiplication Statement (+3) + (+3) + (+3) + (+3) 4 x +3 4 x (-3) (-3) + (-3) + (-3) + (-3) 3 x (+3) - - - - Two groups of -2 remove
Classwork Page 68-69 #5, 6, 10 12, 13, 16, 18, 20