Whole Number & Decimal - Lesson 4 - Addition

The ‘Why’: Why do we need to be able to add?

This lesson starts with students creating a spider diagram on what they think numbers are. Encourage them to think about what you can do with numbers? Some suggestions are included which could be revealed if students are struggling and prompt thoughts in other directions.

The term “Gut, data, gut” is used and is taken from a concept used in Marketing. It suggests that whenever money needs to be spent, you will have a rough idea (a gut instinct if you will) about how much something should cost. You then go seeking data to prove that and then realign this with your gut decision making. The example included is a simple scenario involving a shop.

Students will have some instincts about how to do mental addition. It is still important for them to understand the different techniques. There is a prompt to encourage this in students.

The final activity shows a total bill for four friends who went to lunch and ask them to check their gut feeling about how much they are being asked to pay.

Activities included:

• What are numbers?
• Gut, Data, Gut example
• Commutative law Activity
• Mental Addition Techniques
• Associative law activity
• Written Method Practice
• Problem Solving
• Estimating
• Lunch at a café
• Cryptarithms