Purpose

The purpose of this unit is to introduce the part-whole strategy of bridging to ten.

Achievement Objectives

NA2-1: Use simple additive strategies with whole numbers and fractions.

NA2-3: Know the basic addition and subtraction facts.

Specific Learning Outcomes

Bridge to ten to solve number problems

Required Resource Materials

Blank frames

Counters

Tens frames with 9 fixed dots

Activity

- The teacher poses a problem.
*Josh has 9 oranges and 6 apples. How many does he have altogether?* - Teacher records 9 + 6 on the board.
- Teacher shows a fixed frame of 9 and asks the students to say where the six more should go without touching the tens frame.
- Teacher invites a student who answers that the answer is 15 to come and demonstrate how they got the answer.
- Teacher records the answer on the board.
- If the students “count-on” teacher encourages them to think about adding one and then five by asking the follow up questions:
*Can we work it out without counting-on?*Or*Is there a faster way?* - Repeat with 9 + 7, 9 + 6 with the students demonstrating using either the teacher’s model or individual equipment. Teacher encourages students to explain their thinking.
- Teacher focuses student attention on the importance of making a ten
*Why do you make a ten?*

Note: future lessons could be extended to include 8 + ? and then 18 + ? with the pace depending on the students.