Number · Challenge 10 of 25 · about 7 min
Number-Generating Algorithm
Follow odd and even branches through four deterministic passes.
Your challenge
Take your time. Your answer is checked only when you choose Check Answer.
Curriculum details
- Curriculum code
- VC2M4N10
- Strand
- Number
- Focus
- Follow an algorithm with steps and decisions and identify the resulting pattern.
Interactive visual
An interactive Decide before you act model is ready. Choose Show Visual Trick to reveal and hear one mathematical change at a time.
Visual Trick
Decide before you act
Check whether the current number is odd or even before following the matching arrow.
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Step 1
Send 3 down the odd branch and multiply by 2 to get 6.
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Step 2
Send 6 down the even branch and add 3 to get 9.
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Step 3
Send 9 down the odd branch and multiply by 2 to get 18.
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Step 4
Send 18 down the even branch and add 3 to get 21.
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Step 5
Connect the four passes to the alternating operation pattern.
Your answer
Worked explanation
Why the answer makes sense
- Start by recording 3.
- The four decisions give 3 × 2 = 6, 6 + 3 = 9, 9 × 2 = 18 and 18 + 3 = 21.
- Including the start, the sequence is 3, 6, 9, 18, 21.
This counts as one completed curriculum item. You can replay the model or review it again anytime.