Posted in Additive relationships, Calculating, Conceptual understanding, Fluency, Number sense, Problem solving

NEW! Challenge card pack – Exploring Additive Relationships

New from Digit Dog Challenges – the challenge cards are extended versions of Digit Dog’s popular posts and are now available in packs of 5 with links to Curriculum for Wales 2022.

Each pack has 5 challenge cards, linked to a theme, concept or resource. There is also an overview of how Digit Dog Challenges address the five proficiencies, and links to the relevant Descriptions of Learning in the Mathematics and Numeracy Area of Learning and Experience.

The latest pack contains activities that focus on solving problems that involve additive relationships. They are aimed at Progression Step 2 level descriptions:

Statement of What Matters 1

I have explored additive relationships, using a range of representations. I can add and subtract whole numbers, using a variety of written and mental methods.

Statement of What Matters 2

I can find missing numbers when number bonds are not complete.

Digit Dog and his bones are used as a context for exploring additive relationships and solving non-routine problems that focus on missing numbers.

Packs are available for purchase at

Posted in What's the same / different?

Bottle Top Bugs – What’s the same? What’s different?

Noticing similarities and differences is key to spotting patterns and reasoning mathematically.

Choose 2 bottle top bugs and ask:  “What is the same?” “What is different?”

Explaining what you notice improves your mathematical language and thinking.


Digit Dog and Calculating Cat have each made a set of 3 bugs.

Look at the two sets of bugs and find similarities and differences. Accept all answers. Encourage learners to keep looking for more. Make a list that can be added to during the day / week.

What can you say about the two sets of bugs? What do you notice? Say what you see.

Can you think of anything that is the same about the two sets?

I can see that each set has 3 bugs. Each set has the same number of bugs.

Encourage and model the use of full sentences. You might want to ask learners to start their sentences with I notice that………..

Anything else?

I notice that in each set, the bugs have different coloured eyes.

I notice that the number of spots on all the bugs in both sets is an even number.

I notice that if you add up the number of spots, in each set the total is more than 10 .

I notice that both sets have two bugs with a double.

Can you think of more things that are the same about the two sets?

What about the differences? What is different about the two sets?

I notice that one set has all green bugs and the other has different colours.

Any other differences?

I notice that the total number of spots in each set is different.

I notice that all the bugs in Calculating Cat’s set have more than 7 spots, Digit Dog’s bugs have less than 7.

The total number of spots is different. Digit Dog’s total is half Calculating Cat’s total.

Make up some sets with a partner and look for similarities and differences.

Posted in Calculating, Fluency, Making totals, Strategic competence

Bottle Top Bugs – Making tens

You need a set of Bottle Top Bugs 0 – 10 with spots or numerals

Screenshot 2020-03-26 19.07.14
Screenshot 2020-03-26 19.07.06

Take turns to choose two bugs so that the numbers on their backs add up to 10.

bottletop bugs add to 10

What do you think?

How many pairs of numbers can you find to make 10?

How do you know you have found all the pairs?

What if.…………

…….you looked for 3 numbers which, added together, make 10?

…….you looked for numbers with a difference of 1? What do you notice?

…….you made up some of your own questions?

If you don’t have Bottle Top Bugs you can do the same activity with:

digit cards (download here)

numbers on pieces of paper

number pebbles like these.



number pebbles 2

Posted in Additive relationships, Calculating, Fluency

Bottle Top Bugs – Under the leaf

How many spots are under the leaf?bug under the leaf

Digit Dog is using the bottle top bugs and leaves to create some number problems.

This type of problem encourages learners to think and talk mathematically and use the  link between addition and subtraction.

Ask children to:

  • Explain what the problem is about in their own words.
  • Explain what information they know and what they are trying to find out. How many spots are on the bug they can see? What number of spots cannot be under the leaf?
  • Find a way to work out how many spots are on the bug under the leaf.
  • Describe the strategy they have used. They might:
    • use counters to represent the spots and work out how many more they need to make 10
    • draw pictures of the spots
    • use number bonds – the numbers that add together to make 10.
    • I know that 7 + 3 = 10 so there must be a 3-spot bug under the leaf.
    • I know that 10 – 7 = 3 so there must be a 3-spot bug under the leaf.
  • Convince everyone that their answer is correct. Use sentence starters such as:
    • I know the answer is 3 because ….
    • First of all I…………then I………
    • I know that …….. so…………
  • Write a number sentence
  • Change the bugs – choose two different bugs, work out the total number of spots and then hide one under a leaf.

What if……….

…… tried it with 3 bugs? Work out the total and then hide one bug under a leaf.

…… tried multiplying the numbers? Hide one bug under a leaf but this time say “the product of my numbers is…..”