Grades K–2 · Mathematics
How can ten counters become one bundle?
Ten small counters can be held in one bundle. We call that bundle a ten. It still contains ten counters, even when we count the bundle in one step.
In the diagramTen ones make one tenThe whole contains 23 counters.2 tens3 ones20 + 3 = 23A bundle holds ten; it does not remove counters.
The picture has twenty-three counters. Two bundles hold twenty counters. Three more counters stand outside the bundles. Together they make twenty-three, just as before the counters were bundled.
In the number 23, the 2 tells about two tens. The 3 tells about three single ones. Bundling makes the whole easier to see without changing its size.
About this explanation
Starting knowledge: Count individual objects up to thirty with adult read-aloud support.
Sources
- Common Core State Standards Initiative — Grade 1: Place value and bundles of ten