## 4.5 Learning about Number Relationships

Students can find and create up to four number patterns in this two-part e-example by using a calculator or by shading in values in rectangular grids up to a value of 100.

Choose the sandbox mode or the puzzle mode .

Press the calculator keys to observe or recreate a counting sequence. For example, press 5, _5, =, =, =, ...

You can observe multiple patterns by changing the markers (triangle, square, rhombus, and circle).

Use the slider to adjust the range of numbers on the board (the board does not extend beyond 100).

Explore different counting patterns using the interactive calculator below. Notice the scroll feature that allows the patterns on the hundred board to go up to 100.

- Skip-counting by what numbers will include 100 as part of the pattern? (If counting by threes, start with 3. If counting by eights, start with 8.)
- What pattern do you see when you count by twos and begin with 2?
- What do you notice when you count by twos and begin with 1? Why?
- Will there be a pattern if you skip-count by fives and begin with 3? Why?
- What happens if you skip-count by tens and start with 37? What do you notice?
- How does adding 10 to any number relate to skip-counting by tens beginning with that number?