Madison puts a stamp on an envelope. The stamp measures 1 inch on each side.

Question

How can you find the area of the envelope that is not covered by the stamp?

The envelope is a rectangle that is 4 inches wide and 6 inches long. The square stamp is in the upper right corner of the envelope.

A.
Add the area of the stamp to the area of the envelope:
6
×
4
=
24
,
1
×
1
=
1
,
24
+
1
=
25
square inches.

B.
Subtract the area of the stamp from the area of the envelope:
6
×
4
=
24
,
1
×
1
=
1
,
24
−
1
=
23
square inches.

C.
Add
1
inch to each side of the envelope:
5
×
7
=
35
square inches.

D.
Subtract
1
inch from each side of the envelope:
3
×
5
=
15
square inches.

Answer 1

B. Subtract the area of the stamp from the area of the envelope: 6 × 4 = 24, 1 × 1 = 1, 24 − 1 = 23 square inches.