Build the jumps. Find the answer.

SparkClass

Choose a jump. Watch where you land—and how far you go.

CCSS 2.NBT.B.5 · 2.MD.B.6
Your Number Line
Arcs span exact number-line distances0–100
Open number line Counting up from 38 to 62 with jumps of 2, 20, and 2.
✓

Distance = 2 + 20 + 2 = 24. You landed on 62, but the answer is 24.

Distance
Start38
Now62
Distance24

Keep endpoint and distance apart

Presets show a worked path. Select Clear before asking students to build their own. Arc spacing is proportional to value on the 0–100 line.

1

Count up: the answer is the distance

For 62 − 38, begin at 38—not 62. Jump +2 to 40, +20 to 60, and +2 to 62. Ask, “How far did I travel?” The answer is 2 + 20 + 2 = 24, not the endpoint 62.

2

Add or count back: the answer is the endpoint

For 71 − 46, count back −1, −40, −5 and land on 25. The distance traveled is 46, but the difference is the endpoint, 25.

3

Use compensation without changing the meaning

The 46 + 38 preset jumps +40 and then −2. Read the path as 46 + 40 − 2 = 84. The answer is still the endpoint 84—not the 42 units traveled.

4

Prompt before revealing

After Clear, ask students to predict a useful first jump. “Friendly jump” moves to the next ten in the direction of the target, or directly to the target when it is closer.

CCSS alignment: 2.NBT.B.5—fluently add and subtract within 100 using strategies based on place value and properties of operations. 2.MD.B.6—represent whole-number sums and differences within 100 on a number line diagram.