27122021 Negative numbers MATHSWATCH CLIP 23 68 GRADE

27/12/2021 Negative numbers MATHSWATCH CLIP 23, 68 GRADE 2, 3 L. O. To be able to § Use addition and subtraction with negatives § Use negative numbers in real life contexts Key Words add, subtract, positive, negative, direction, order, bigger, smaller, result, calculate Starter:

27/12/2021 Negative numbers MATHSWATCH CLIP 23, 68 GRADE 2, 3 L. O. To be able to § Use addition and subtraction with negatives § Use negative numbers in real life contexts Key Words add, subtract, positive, negative, direction, order, bigger, smaller, result, calculate Starter answers:

27/12/2021 Negative numbers MATHSWATCH CLIP 23, 68 GRADE 2, 3 ADDING AND SUBTRACTING WITH NEGATIVES Watch this video clip about this topic – come back to it during the lesson if you need to Negatives: Addition and Subtraction Video – Corbettmaths www. corbettmaths. com/2013/06/08/negatives-addition-and-subtraction-2

27/12/2021 Negative numbers MATHSWATCH CLIP 23, 68 GRADE 2, 3

27/12/2021 Negative numbers MATHSWATCH CLIP 23, 68 GRADE 2, 3 QUICK CALCULATIONS! What’s the difference…?

MATHSWATCH CLIP 23, 68 GRADE 2, 3 Negative numbers Difficulty * o. C 60 60 50 50 40 30 20 20 10 10 0 0 -10 -20 -30 40 degrees

MATHSWATCH CLIP 23, 68 GRADE 2, 3 Negative numbers Difficulty * o. C 60 60 50 50 40 30 20 20 10 10 0 0 -10 -20 -30 15 degrees

MATHSWATCH CLIP 23, 68 GRADE 2, 3 Negative numbers Difficulty ** o. C 60 60 50 50 40 30 20 20 10 10 0 0 -10 -20 -30 30 degrees

MATHSWATCH CLIP 23, 68 GRADE 2, 3 Negative numbers Difficulty ** o. C 60 60 50 50 40 30 20 20 10 10 0 0 -10 -20 -30 65 degrees

MATHSWATCH CLIP 23, 68 GRADE 2, 3 Negative numbers Difficulty ** o. C 60 60 50 50 40 30 20 20 10 10 0 0 -10 -20 -30 15 degrees

MATHSWATCH CLIP 23, 68 GRADE 2, 3 Negative numbers Difficulty ** o. C 60 60 50 50 40 30 20 20 10 10 0 0 -10 -20 -30 10 degrees

MATHSWATCH CLIP 23, 68 GRADE 2, 3 Negative numbers Difficulty ** o. C 60 60 50 50 40 30 20 20 10 10 0 0 -10 -20 -30 70 degrees

Difficulty * Negative numbers What is the difference between: 1. 2. 3. 4. 5. 6. 7. 4 and – 8 3 and -1 6 and -7 10 and -1 6 and -2 5 and -9 3 and -3 Positive numbers MATHSWATCH CLIP 23, 68 GRADE 2, 3

27/12/2021 Negative numbers What is the difference between: 1. 2. 3. 4. 5. 6. 7. 4 and – 8 = 12 3 and -1 = 4 6 and -7 = 13 10 and -1 = 11 6 and -2 = 8 5 and -9 = 14 3 and -3 = 6 Positive numbers MATHSWATCH CLIP 23, 68 GRADE 2, 3

Difficulty ** Negative numbers MATHSWATCH CLIP 23, 68 GRADE 2, 3

27/12/2021 MATHSWATCH CLIP 23, 68 GRADE 2, 3 Negative numbers 35

27/12/2021 Negative numbers MATHSWATCH CLIP 23, 68 GRADE 2, 3 When we add and subtract negative numbers, we imagine a number line 3+2 Where we start Which direction we move =5 How far we move + -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9

27/12/2021 Negative numbers MATHSWATCH CLIP 23, 68 GRADE 2, 3 -3 + 2 = -1 + -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9

Negative numbers 27/12/2021 - -5 MATHSWATCH CLIP 23, 68 GRADE 2, 3 -4 -3 -2 -1 0 1 Move Direction to move Start -3 + 5 = 2 2 3 4 5 +

27/12/2021 Negative numbers – 2 + 5 = 3 -2 3 MATHSWATCH CLIP 23, 68 GRADE 2, 3

Difficulty */** Negative numbers Try these! 1 -1+3= 6 -8+8= 2 -4+5= 7 -9+6= 3 -6+9= 8 -5+4= 4 - 7 + 12 = 9 - 10 + 20 = 5 - 6 + 10 = 10 - 15 + 8 = MATHSWATCH CLIP 23, 68 GRADE 2, 3

Negative numbers 27/12/2021 MATHSWATCH CLIP 23, 68 GRADE 2, 3 Answers! 1 -1+3= 2 6 -8+8= 0 2 -4+5= 1 7 -9+6= -3 3 -6+9= 3 8 -5+4= -1 4 - 7 + 12 = 5 9 - 10 + 20 = 10 5 - 6 + 10 = 4 10 - 15 + 8 = -7

27/12/2021 Negative numbers MATHSWATCH CLIP 23, 68 GRADE 2, 3 -2 - 3 = -5 - -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9

Negative numbers 27/12/2021 - -5 MATHSWATCH CLIP 23, 68 GRADE 2, 3 -4 -3 -2 -1 0 1 Move Direction to move Start 3 - 5 = -2 2 3 4 5 +

Negative numbers 27/12/2021 - -5 MATHSWATCH CLIP 23, 68 GRADE 2, 3 -4 -3 -2 -1 0 1 Move Direction to move Start 2 + 3 - 7 = -2 2 3 4 5 +

27/12/2021 Negative numbers 5 – 8 = – 3 -3 5 MATHSWATCH CLIP 23, 68 GRADE 2, 3

Negative numbers Difficulty */** Try these! 1 7 -3= 6 -1 -1= 2 4 -4= 7 -2 -3= 3 3 -5= 8 -5 -3= 4 1 -8= 9 -7 -3= 5 0 -6= 10 - 3 - 12 = MATHSWATCH CLIP 23, 68 GRADE 2, 3

Negative numbers 27/12/2021 MATHSWATCH CLIP 23, 68 GRADE 2, 3 Answers! 1 7 -3= 4 6 -1 -1= -2 2 4 -4= 0 7 -2 -3= -5 3 3 -5= -2 8 -5 -3= -8 4 1 -8= -7 9 -7 -3= -10 5 0 -6= -6 10 - 3 - 12 = -15

Negative numbers 27/12/2021 1) 5– 7 2) 3– 5 3) 1– 4 4) 2– 6 5) 5 – 10 6) -1 – 2 7) -2 – 3 8) -3 – 1 9) 0– 3 10) -2 + 5 11) -1 + 6 12) -5 + 7 13) -4 + 7 14) -4 + 4 15) -3 + 8 16) -5 + 2 17) -3 + 1 18) -2 + 2 19) 12 – 20 20) -15 – 10 21) -8 + 20 22) -14 + 7 23) -30 – 20 24) 15 – 20 25) 12 – 20 + 10 27) -1 + 2 – 3 + 4 – 5 + 6 – 7 + 8 – 9 + 10 26) -10 + 4 – 10 MATHSWATCH CLIP 23, 68 GRADE 2, 3

MATHSWATCH CLIP 23, 68 GRADE 2, 3 Negative numbers 27/12/2021 1) 5– 7 -2 2) 3– 5 -2 3) 1– 4 -3 4) 2– 6 -4 5) 5 – 10 -5 6) -1 – 2 -3 7) -2 – 3 -5 8) -3 – 1 -4 9) 0– 3 -3 10) -2 + 5 3 11) -1 + 6 5 12) -5 + 7 2 13) -4 + 7 3 14) -4 + 4 0 15) -3 + 8 5 16) -5 + 2 -3 17) -3 + 1 -2 18) -2 + 2 0 19) 12 – 20 -8 20) -15 – 10 - 25 21) -8 + 20 12 22) -14 + 7 -7 23) -30 – 20 - 50 24) 15 – 20 -5 25) 12 – 20 + 10 27) -1 + 2 – 3 + 4 – 5 + 6 – 7 + 8 – 9 + 10 2 26) -10 + 4 – 10 - 16 5

27/12/2021 Negative numbers MATHSWATCH CLIP 23, 68 GRADE 2, 3 Discussion - how do we solve problems like these? 4 + -2 2 - -3 -3 + -1 -5 - -7

27/12/2021 Negative numbers General rule for signs between the numbers: +- - -- + MATHSWATCH CLIP 23, 68 GRADE 2, 3

27/12/2021 Negative numbers MATHSWATCH CLIP 23, 68 GRADE 2, 3 4 + -2 = 2 - - -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9

27/12/2021 Negative numbers MATHSWATCH CLIP 23, 68 GRADE 2, 3 -3 + -1 = -4 - -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9

27/12/2021 Negative numbers MATHSWATCH CLIP 23, 68 GRADE 2, 3 2 - -3 = 5 + + -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9

27/12/2021 Negative numbers MATHSWATCH CLIP 23, 68 GRADE 2, 3 -5 - -7 = 2 + + -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9

Negative numbers 27/12/2021 - -5 MATHSWATCH CLIP 23, 68 GRADE 2, 3 -4 -3 -2 -1 0 Move Direction to move Start 4+-3 =1 1 2 3 4 5 +

Negative numbers Difficulty */** MATHSWATCH CLIP 23, 68 GRADE 2, 3 1) 5 + -2 2) 3 - -3 3) -5 + -1 4) -6 - 3 5) 8+4 6) 9 - -9 7) 0 + -7 8) -8 - -10 9) 6 -6 10) 6 - -7 + -3 11) 6 + 5 - -1 12) -2 - 5 - -1 13) 0 --4 --4+4 14) -1 - - 1 - -1

Negative numbers 27/12/2021 MATHSWATCH CLIP 23, 68 GRADE 2, 3 1) 5 + -2 3 2) 3 - -3 6 3) -5 + -1 -6 4) -6 - 3 -9 5) 8+4 12 6) 9 - -9 18 7) 0 + -7 -7 8) -8 - -10 2 9) 6 -6 0 12) -2 - 5 - -1 10 10) 6 - -7 + -3 11) 13) 0 --4 --4+4 12 6 + 5 - -1 12 14) -1 - - 1 - -1 0 -6