Add and Subtract with Transparency Number Lines

Slide 1: (title)
Slide 2: Addition: This example of addition requires the long line for our first number, the short line labeled “addition of
second number” and 7 red squares.
Slide 3: Place & count red squares for first number 3 on long number line.
Slide 4: Place beginning of short line above first number 3 on long line.
Slide 5: Place & count red squares for second number 4 on short number line.
Slide 6: Transfer/add 4 red squares from short line to 3 red squares on long line to equal answer of 7.
Slide 7: 3 plus 4 equals 7. 3 + 4 = 7
Slide 8: Subtraction: This example of subtraction requires the long line for our first number, the short line labeled
“subtraction of second number” and 13 red squares.
Slide 9: Place & count red squares for first number 13 on the long number line.
Slide 10: Careful! The zero or beginning point of the subtraction line is on the right side.
Slide 11: Place beginning of short line above first number 13 on long line.
Slide 12: Transfer/subtract red squares from first number 13 on long line to second number 5 on short line. Count up to
second number 5 on the short line as we count down to answer of 8 on the long line.
Slide 13: 13 minus 5 = 8. 13 – 5 = 8