It's a Magic MishMash

This knowledge-based activity is designed to help students to recognise the skip-counting patterns in a range of numbers and apply the rule to their own set of numbers.
Prior knowledge and experience with skip-counting is necessary. For number sequences beyond 100, use a thousands book (Material Master 4-7) to show the effect of skip-counting in increments of 100.
As an extension, ask the students to make up their own magic number machine and write the rules for what will happen in each tube as the numbers pass through. See whether their classmate can guess what the rules are. Encourage the students to record their thinking and the number sequence to help them identify a pattern.
As another extension, you could give the students this problem:
“Irwin and Xanthe found some other magic number machines. They put 248 into each machine. Here are the first three numbers that came out of each machine:
Machine 1: 298 348 398 (skip-counting in 50s)
Machine 2: 238 228 218 (subtracting 10 each time)
Machine 3: 448 648 848 (skip-counting in 200s)
What is each machine doing to the number?”
 

Answers to  Activity

1. Skip-counting in 100s or adding 100 to the previous number
2. a. 113, 213, 313
b. 127, 227, 327
c. 145, 245, 345
3. Skip-counting in 2s or adding 2 to the previous number
4. a. 214, 216, 218, 220, 222
b. 443, 445, 447, 449, 451
c. 704, 706, 708, 710, 712
d. 599, 601, 603, 605, 607