Term 2 Big Ideas:
Gr. 2 – Development of computational fluency in addition and subtraction with numbers to 100 requires an understanding of place value

Adding & Subtracting Double Digits with Regrouping
   

Video:  Subtraction with Regrouping

Gr. 3 – Development of computational fluency in addition, subtraction and multiplication of whole numbers requires flexible decomposing and composing
Multiplication is creating equal groups of numbers or objects.
Example:  How many groups? (3)   How many in each group? (4)
3 x 4 = 12

The numbers or objects can be arranged in an array.
An array is arranging a number of objects in equal rows and columns.
Example:  How many rows? (5)   How many in each row? (6)
5 x 6 = 30

Besides creating equal groups or drawing arrays, repeated addition of a number can be used to find the answer or product.

References:
https://www.youtube.com/watch?v=QphXFi30aFk
https://www.youtube.com/watch?v=MeidqzJNA2o
Multiply Chart 1      Multiply Chart 2

Patterning Big Ideas:
*The regular change in increasing patterns can be identified and used to make generalizations
*Regular increases and decreases in patterns can be identified and used to make generalizations
Vocabulary:  pattern, attribute, repeat, increase, decrease, pattern core

 Vocabulary:  digit, add, subtract, sum, difference, compose & decompose, addend & minuend

Subtraction Across Zeros:
https://www.youtube.com/watch?v=r4arfV3bn7g&t=109s
https://www.youtube.com/watch?v=uW7KX45ETp8