Assistant Principal Report

Strengthening number sense at home: Partitioning (part-part-whole)

What are teen numbers?

Teen numbers are numbers between 11-19. These numbers can be tricky to learn as they are different from 1-10 and do not follow the same naming patterns for 20 and above.

Learning the teen numbers and being able to count to 20 is an important skill for your child to learn. You can support your child to become confident with teen numbers by encouraging them to count to, and backwards from, 20. Practising this skill at home will help your child feel confident counting to 20.

Tips

Here are some easy and fun ways to help your child develop their understanding of teen numbers:

At home

When cooking eggs, take a carton of eggs and count the eggs together. Put 2 eggs on the bench and count the eggs remaining in the carton, demonstrating that 12 is 10 and 2 more.
Build block towers of different heights using 11-19 blocks. Build the first 10 blocks quickly and then add on some more. For more practice counting teen numbers, recount the number of blocks in each tower at the end. Ask your child how many more than 10 the number is. For example, ‘15 is 10 and how many more?’

If your child is unsure of the answer, count together to 10, pause and then say ’15 is

10 and 1, 2, 3, 4, 5 more', pointing to each block greater than 10 as you count.

Take a handful of a healthy snack such as sultanas. Count how many there are. Ask them, ‘is it a teen number?’ Add or take away sultanas to make the snack a teen number. Ask your child to tell how many more than 10 the total is; for example, 13 is 10 and 3 more.
Write the numbers 11-19 on scraps of paper and place in order. When your child is not looking, remove one of the numbers and remove the gap created. Have them tell you which number is missing. Return the number and then take it in turns to find the missing number. Ask your child to describe the missing number as ‘10 and how many more?’

At the supermarket

Look at the aisles of larger supermarkets. Ask your child to show you which aisles have teen numbers. What will the next aisle be? Have your child lead you to a teen aisle or tell you what is in the aisle
Encourage your child to look for teen numbers at the supermarket. They might find teen numbers written in price tags, barcodes or signs. Can they find 10 teen numbers?
Ask your child to count each item as they are taken out of the trolley or basket. When they reach a teen number, ask them to describe the next number as ‘10 and how many’ more; for example, ‘11 is 10 and 1 more’.

At the park

Play hopscotch with the numbers 11-20 instead of 1-10. Including 20 helps your child what comes after the teen numbers. Ask them to call out the number that the stone lands on before they hop through the course, counting each number
Have your child find things at the park that can be counted (fence rails, trees). Tell them the goal is to find something that has a teen number as a total.
Collect natural items like sticks and stones. Use them to represent a teen number; for example, make 14 from 10 sticks and 4 stones. Ask your child, ‘how many more than 10 is the total?’. Collect more items to build another teen number.

Further information To access other videos and tip sheets in this series as well as further tips, information and links for parents and carers, see: Mathematics and numeracy at home

For further information on supporting your child’s education, see: Supporting your child's education | vic.gov.au

Dani Bird

Assistant Principle