Math Cartoon 4
1
1. Now that we know our basic multiplication facts, lets figure out how we can do more complicated problems. Look at the 12 x 14 array shown here. Find out the number of dots in the array. (The candy store scenario might help.)
2. Here is another array (13 x 17). Find out how many dots are in it.
3. It can be a real drag drawing tons of dots in order to do multiplication. Another way to think about multiplication is in an area setting. For example, if we have a
Cartoon Math 4
2
rectangle that is 3 units tall and 4 units wide, its area is 14 square units. lets So figure out the area of a rectangle that is 12 units tall and 14 units wide. First we will draw our rectangle. Then we can split our rectangle into four smaller rectangular regions. We might think of 12 as 10 + 2 and 14 as 10 + 4. 14 10 4
12
10
2 What is the area of each of the four small rectangles? What is the area of the whole rectangle? 4. Use the rectangle below to calculate 11 x 15.
5. Draw your own rectangles to calculate each of the following: (a) 17 x 13 (b) 13 x 13 (c) 16 x 12 (d) 21 x 14
6. Now, lets move on ...