Mental Strategies & the Seen Element

Question 1

What are the different addition Strategies?

Answer 1

The main methods for adding mentally:-
1. Partitioning – both numbers
2. Partitioning – one number only
3. Compensation
4. Known Facts
5. Rearranging
6. Repeated operations

Question 2

What is Partitioning – both numbers?

Answer 2

56 + 87 =

50 6 80 7
50 + 80 =
6 + 7 =

Question 3

What is Partitioning - one number only?

Answer 3

47 + 26 =

40 + 7

40 + 26 = 66
66 + 7 = 73

Question 4

What is compensation?

Answer 4

37 + 19
37 + (19 + 1)
37 + 20 = 57
57 - 1 = 56

Question 5

What is known facts?

Answer 5

Could be related to doubles 46 + 46 = 92

Question 6

What are the Subtraction Strategies?

Answer 6

The main methods for subtracting mentally:-
1. Using partitioning (one number – count
back)
2. Compensation
3. Known Facts
4. Use of Inverse
5. Bridging to the next multiple of 10 or 100
6. Using Equivalences

Question 7

What are the different structure/Theory?

Answer 7

Aggregation, Augmentation, Augmentation structure, Aggregation structure,

Question 8

What different laws is there?

Answer 8

Commutative: a + b = b + a (4 + 5 = 5 + 4)

Associative: a + ( b + c) = (a + b) + c
12 + (6 + 2) = (12 + 6) + 2