Numbers to 20 · Usually met around P1
Subitising
Know the pattern: 5 is four corners and the middle.
How to do it
Method
Know the pattern: 5 is four corners and the middle
⚄ and ⚂: 5 and 3 make 8
Another way
Ten frames
A full row is 5; 2 more is 7
In full
With a few things you need not count one by one; you can see how many: four corners and a middle dot on a dice is 5, and two rows of 3 is 6. A ten frame has 5 to a row: a full top row and 2 more is 7, and just 1 space empty is 9. When you can't see it at once, split the dots into small groups you know, like 6 as 3 and 3, and put them together. Or use fingers: one hand is 5, then add fingers.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
Without counting each dot: how many dots are on the two dice altogether?
Show the answer and working
Answer: 8
Know the patterns: 3 on the left, 5 on the right, and 3 and 5 make 8.
Example 2
How many spaces in the ten frame are still empty?
Show the answer and working
Answer: 7
A ten frame has 10 spaces and 3 are filled, so 7 are empty.
Example 3
This dice shows more than 4.
True or false?
Show the answer and working
Answer: False
You can see at a glance the dice shows 1; compare it with 4.
Practise it in the game →Numbers to 20 · Free to start, unlimited questions, no download