Counting forwards and backwards
Count forwards and backwards in steps of 3 from 0
What a learner can do afterwards
- Count 3, 6, 9, 12, 15 … up to at least 30
- Count backwards in 3s from 30
- Identify the next number in a sequence of multiples of 3
The lesson
You already know how to count by 2s. Counting by 3s works the same way, except you add 3 each time instead of 2. Start at 0: 0, 3, 6, 9, 12, and keep going. Every number you land on is called a multiple of three.
Zara stacks blocks in towers of three. She counts the towers: 3, 6, 9, 12. She has four towers, twelve blocks in all.
To count backward by 3s, do the opposite: take away 3 each time instead of adding it. If you lose track, count forward by 3s until you reach your starting number, then say the numbers back in reverse.
Add 3 to count forward, take away 3 to count backward: 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 30.
Watch it
Where it sits
Learn first
This opens up
Nothing builds on it yet.
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.