Number Path and Hop Count Lab

Pick a starting number on a path from 0 to 20. Hop forward or backward to see where you land. Record your hops in a table and discover how forward and backward hops are connected.

Guided Experiment: Forward and Backward Hops Investigation

Start at 7. If you hop forward 3 spaces, then hop backward 3 spaces, where do you think you will land? Write your prediction.

Write your hypothesis in the Lab Report panel, then click Next.

Set Up Your Hop

Start
7
Hops
3
Direction
Equation
7 + 3 = 10

Number Path (0 to 20)

0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
StartHopsLanding

Controls

0 / 500
0 / 500
0 / 500

Reference Guide

Counting On

Counting on means starting at a number and hopping forward one space at a time. Each forward hop adds 1 to where you are standing.

Start 7, hop forward 3. 8, 9, 10.

Counting on is a faster way to add. Instead of counting every number from zero, you start at one number and hop the rest.

Counting Back

Counting back means starting at a number and hopping backward one space at a time. Each backward hop takes away 1.

Start 10, hop back 4. 9, 8, 7, 6.

Counting back helps you subtract. Start with the bigger number and hop backward the number of times you are taking away.

Forward Hops Are Addition

Hopping forward on a number path is the same as addition. The start number plus the number of hops equals your landing spot.

Start 5, hop forward 3.
5 + 3 = 8. You land on 8.

If you know how to hop forward, you can solve any addition problem by starting at the first number.

Backward Hops Are Subtraction

Hopping backward on a number path is the same as subtraction. The start number minus the number of hops equals your landing spot.

Start 9, hop back 4.
9 - 4 = 5. You land on 5.

Forward and backward hops are opposites. If you hop forward 3 and then backward 3, you return to where you started.

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