Mathematics workshop
Number composition
Five counters make one whole. We can split it into two, three or more parts. The numbers we add are called addends.
Theory
One whole, two parts
At the start, two counters and three counters make five altogether. Choose a counter and move it to another part. There are still five altogether.
Total: 5
2 + 3 = 5
Choose a counter, then a part.
More than two parts
One, two and two also make five: 1 + 2 + 2 = 5. Add a part and split the counters another way. Swapping the same parts does not make a new split.
Total: 5
1 + 2 + 2 = 5
Choose a counter, then a part.
A part can be empty
An empty part has zero counters. 2 + 3 + 0 = 5: the empty part does not change the whole. Move a counter into it and see what changes.
Total: 5
2 + 3 + 0 = 5
Choose a counter, then a part.
Every pair that makes six
Start with 0 and 6. Move one counter at a time and save each pair. 1 + 5 and 5 + 1 are the same pair. Finish with two equal parts.
Total: 6
0 + 6 = 6
Choose a counter, then a part.
Pairs found: 0/4
What's under the cover?
There are five altogether. We can see one counter in the first part and two in the third. How many are under the cover? Open it to check your guess.
Total: 5
1 + ? + 2 = 5
Practice
Choose a counter, then the part to move it to. Add parts; removing a part moves its counters into its neighbour. The total stays the same.
Total: 5
2 + 3 = 5
Choose a counter, then a part.
Games
Split the whole another way and check your construction, or choose the hidden part’s number to check it straight away.
Start: 2 + 3 = 5
Total: 5
Choose a counter, then a part.