Measuring Magnification

2.3 based on 9 ratings

Updated on Feb 08, 2012

Grade Level: 3rd - 6th; Type: Physical Science


To investigate how optical distances change the apparent size of an object as seen through a magnifying lens.

Research Questions:

  • How does a magnifying lens make things look larger?
  • Does the distance the lens is from the object affect the optical size of the object?

Things look larger when you look at them through a magnifying lens. Magnifying lens make it easier to see small things. Magnifying lens help people see things better. Magnifying lens are used in eyeglasses, telescopes, microscopes, binoculars, and magnifying glasses.


  • large magnifying glass
  • ruler
  • clear tape
  • wax paper
  • fine tip marker
  • scissors
  • modeling clay
  • word cut from a magazine

Experimental Procedure

  1. Gather the necessary materials.
  2. Place a piece of clear tape about the same length as the diameter of the lens of the magnifying glass on the wax paper. Use the ruler to mark inches, half-inches, quarter-inches, and eighth-inches along the tape. Then place the tape across the diameter of the lens.
  3. Measure the length of the word cut from a magazine. Record the measurement.
  4. Use the modeling clay to stand the ruler upright on a table.
  5. Set the word cut from a magazine beside the standing ruler.
  6. Start by holding the magnifying glass 10 inches above the word. Record the measurement of the word at 10 inches. Then hold the magnifying glass 9 inches above the word. Again record the measurement. Continue moving the magnifying glass closer to the word in 1-inch increments, recording the size of the word. Record the measurements.
  7. Magnification is the size of the word as seen through the magnifying glass divided by the actual size of the word. Use a calculator to determine the magnification of the magnifying glass.
  8. Analyze the data and draw a conclusion.

Terms/Concepts: magnification: to appear larger power: the degree to which something appears larger lens: a piece of glass or plastic that is used to make something appear larger or more clear optical distance: the distance a lens is to the object being looked at optics: the study of how light travels through different things such as a magnifying lens; Magnifying lens make it easier to see small things and to see things more clearly.


“Magnification” “Simple Magnification” at “How Does a Magnifying Glass Work?” at “How Does a Magnifying Lens Work? By Diana Doherty at

Nancy Rogers Bosse has been involved in education for over forty years - first as a student, then as a teacher, and currently as a curriculum developer. For the last fifteen years she has combined a career in freelance curriculum development with parenthood - another important facet of education and probably the most challenging. Nancy lives in Henderson, Nevada with husband and their three teenagers.

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