Activities at Home

The Greatest Difference

Arranging the digits in these problems will present a challenge to your child, but only until he or she catches on to the pattern.

What You Need:

Help with Opening PDF Files

What You and Your Child Will Do:

  1. Show your child the worksheet and draw attention to the digits located in the cloud—1, 7, 3, and 2.
  2. Explain that, by writing each of these digits in one of the boxes below, it is possible to make two 2-digit numbers. Challenge your child to make 2-digit numbers so that subtracting one from the other will give the greatest possible answer, or difference.
  3. Many children will start by writing the digits randomly and then subtract—perhaps this way.
    greatest difference chart
  4. Point out that, even if the subtraction is correct, it may be possible to arrange these same digits in another way to give a greater difference.
  5. It may take many tries until your child recognizes this pattern. By arranging the digits so that you are subtracting the least possible number from the greatest possible number, you will get the greatest possible difference.
  6. Have your child work the first four problems. (The answers follow.)
    4 greatest difference charts

More to Do:

Once your child has caught on to the pattern, suggest that he or she write four other digits in the spaces in each of the other sections of the worksheet and then find the greatest possible difference for these numbers.