# Multiple Ways to Add and Subtract Teacher’s Notes

These exercises and activities are for students to use independently of the teacher to practise number properties.

### Curriculum reference:

Number levels 3 to 4

### Numeracy Project book reference:

These exercises and activities follow from a teaching episode based on Book 5 Page 54 and are for those students who are able to use the associated number properties.

### Prior knowledge. Students should be able to…

• Instantly recall multiplication facts to tens
• Instantly recall factors of numbers generated by multiplication facts to ten
• Familiarisation with the use of brackets in notation
• Multiply two digit numbers by a single digit number using the distributive law
eg 15 x 6 = (10 x 6) + (5 x 6) = 90

### During these activities students will meet:

True/false questions

### Background:

The exercises have been set up in the following way.
Exercise 1: requires the students to use the distributive law and write it out
Exercise 2: is a true/false activity

### Homework Exercises

Only include examples like Exercise 1.

### Number generalisation

Ideas that can be developed from this activity:
ac + bc = (a + b)c