When objects are in equal groups, you do not need to count them one by one. Skip count by the size of a group: say one number for each group. Groups of 2 go 2, 4, 6. Groups of 5 go 5, 10, 15. Groups of 10 go 10, 20, 30. If some are loose, skip count the groups first and then count on the loose ones. To make groups from a collection, skip count until you reach the total and count the numbers you said.
Explore this idea with maths tools
Maths you can move
Build 8 + 5
Tap two gold counters to fill the ten-frame.
8 in the frame + 5 waiting. The total stays the same.
Words to know
- group
- a set of objects kept together
- skip count
- count in jumps, such as 5, 10, 15
- loose
- not in a group
Worked examples
The stars are in 4 groups of 5. How many stars altogether?
- 1.Each group has 5, so skip count by 5.
- 2.Say one number for each group: 5, 10, 15, 20.
- 3.There are 4 groups, and the last number is the total.
= 20
Put the 30 shells into groups of 10. How many groups can you make?
- 1.Skip count by 10 until you reach 30: 10, 20, 30.
- 2.You said 3 numbers.
- 3.So there are 3 groups.
= 3
There are 3 groups of 10 and 4 loose marbles. How many altogether?
- 1.Skip count the groups: 10, 20, 30.
- 2.Count on the loose ones: 31, 32, 33, 34.
- 3.There are 34 altogether.
= 34
For parents
Method: Skip count by the group size, one number for each group.
What to say: How many in each group? How many groups? Have you counted every group and the loose ones?
Common mistakes:
- Counts the groups, not the objects inside them.
- Gives the size of one group instead of the total (or the number of groups).
- Counts only the groups first seen and leaves out the added groups, loose objects or second kind of group.
- Loses a group when skip counting, so the answer is one group too small.
- Gives how many there are altogether instead of how many groups can be made.
- Adds the number of groups to the size of a group.