The multiples of 10
Understand that the multiples of 10 (10, 20, 30 … 90) represent one to nine tens and 0 ones
What a learner can do afterwards
- Explain that 30 means 3 tens and 0 ones
- Represent 50 using 5 tens rods and no unit cubes
- Match decade numbers to their tens representation
The lesson
You already know that a ten is ten ones bundled together. Now count using only whole tens: 10, 20, 30, 40, 50, 60, 70, 80, and 90. Each of these numbers is built from tens alone, with nothing extra left over as loose ones.
Mia lines up 5 tens rods and no loose cubes. She counts 10, 20, 30, 40, 50. That number, 50, means 5 tens and 0 ones.
Look at the ones place in 30, 50, or 90. It always shows a zero. That zero is a placeholder. It means there are no loose ones, only whole tens.
Every multiple of ten is made only of whole tens, and the zero in the ones place shows nothing is left over.
Watch it
Where it sits
Learn first
This opens up
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.