## Grade 2 & Grade 3 Two digit number

**Number Sense for 2 and 3 digit number is no different than number sense for number to 10. **

**Identify the quantity & Express multiple ways using place value units**

**words, multiplication units, expanded expressions, expander cards, blocks to 100 grids to number lines. STOP the pictures of tallies and circles. Build imagery that links to number so that students can use expressions. ****ADDITIVE COMPOSITION focus only on parts inside the whole to begin.**

**Equal**

*record expressions and connect expressions multiple ways Associative & Commutative Properties emerge*

**Magnitude & Density**

How close to? How far away from? Relate to other numbers. Use referents of decades, (multiples of 5 & 10) , 50 and 100 and the language of more than, less than, between, near, about. Stretch area models into number lines. **COMPARE **

**Inverses**

*understand the relationship and how to record it using the addition and the subtraction signs. Missing parts can be explained when you have solid number sense. Relate using the grid and explaining the space. Relate using the number line and explaining the distances between.*

**Build 2 & 3 digit with your students using the BERCS DECKS listed below.**

The Two Digit Number and Three Digit Number books contain blackline masters and support pages that help you develop individual and whole class practice routines. They are ordered separately. ** Just list what you want in an email to glorway@thinking101.ca. **

** Decks are in colour and laminated. Your cost $12 per deck. The Two Digit Book is $39.99 and the Three Digit Book is $29.99. I accept Visa, e transfer and school PO or personal cheques. **

**Get in the habit of building lists of expressions as students explain what they see, then encourage students to look for patterns in the lists so they are focused on organizing data. **

## Introduce the 100 grid #1 August 15 2018

The page below is meant to provide you guidance as you work with 2 digit number. There are several more pages of explanation here. HUNDRED GRID Hand out April 2018 .

It is part of a booklet of materials I am developing. Please respect my copyright and do not reproduce for others.. Thanks.

Download the sheet above here.

## NUMBER LINES MATTER

**Here are 2 powerpoints for thinking about how to stretch number from an area model to a number line model. Two Digit number line intro 2019**

## The samples below are Grade 2 thinkers as they solve problems that involve two digit numbers. This thinking has developed from understanding the imagery of the grid.