Adding in Parts
These exercises and activities are designed for students to use independently to practise number properties.
Number Framework domain and stage:
Addition and Subtraction – Advanced additive to advanced multiplicative
Number, level 3
Numeracy Project book reference:
These activities can be used to follow the teaching episodes based on Book 5 pg 29 and are for those students who are able to use the associated number properties.
Prior knowledge. Students should be able to:
- split a whole number into parts eg. 8 = 5 + 3, 27 = 25 + 2
- make numbers up to a tidy number
- add and subtract tenths to make a decimals number into a whole number
During these activities students will meet:
- addition of whole numbers up to three digits
- addition of decimals
- use of equals
- use > and <
The exercises have been set up in the following way:
Exercise 1: Adding on to a two digit number by splitting one number into parts.
Exercise 2: Adding on to a three digit number by splitting one number into parts.
Exercise 3: Adding tenths to get a whole number.
Exercise 4: Adding decimal numbers with one decimal place by making one number into a whole number and adjusting the other number.
Exercise 5: Recognising true statements based on adjusting one number up and the other number down.
Exercise 6: Finding the missing number to make a true statement based on adjusting one number up and the other number down.
Exercise 7: Students write their own true statement and describe the relationship between the new numbers.
Exercise 8: Students explain relationships based on adjusting numbers up and/or down. This needs to be followed by class discussion.
Exercise 9: Generalising the relationship by using a variable with a number
Practice exercises with answers:
Related activities and web links:
There are two addition squares. Students cut out the nine squares and rearrange them to form a 3 by 3 square. Where two squares are touching the expressions on the sides must be equivalent.