I made a valentine that needs 58 cents in postage.  When I looked for stamps in my desk, this is what I found:

• 50 cent stamp
• 37 cent stamp
• 25 cent stamp
• 12 cent stamp
• 7 cent stamp
• 5 cent stamp
• 4 cent stamp

Which stamps can I use?  (I don't want to use more postage than is needed).

For 4th and 5th grades:  Suppose I had 2 of each stamp listed above.  Which stamps should I use if I needed $1.67?