Page 144 - NUMINO TG_4A

09Door Frame Method Unit

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2 . Multiply. b. 4 2 7 c. 8 0 9 2. Students will find the product of a 3-digit
30 50 number by a multiple of ten.
a. 2 5 6
70 0 0 Show students how to multiply a 3-digit
+4 0 4 5 0 number by a 2-digit number.
0 +1 2 8 1 0 Example: 857 26
+1 7 9 2 0 4 0,4 5 0
1 2,8 1 0 Multiply the ones.
1 7,9 2 0 857 857 6 5,142
26 Multiply the tens.
Learn how to multiply 857 by 26. 857 20 17,140
5142 Find the sum of the products in step 1
857 857 857 +17140 and step 2.
26 26 26 5,142 17,140 22,282
2 2,2 8 2
5142 5142 3. Have the students fill in the missing digits
17140 to complete each multiplication problem.

3 . Fill in the blanks by using the method above.

a. 3 5 0 b. 4 9 7 c. 8 3 7
28 36 49

2 80 0 2 9 82 7 53 3

7 0 00 14 910 3 3 4 80

9 ,8 0 0 1 7,8 9 2 4 1,0 1 3

9. Door Frame Method 77

Problem:
In an auditorium, there are 20 rows with 152 red chairs in each row and 28 rows with 135 blue chairs in each
row. Which color chairs are there more of and how many more are there? Find the solution and answer.
Answer:
Red chair 152 20 3,040
Blue chair 135 28 3,780
Blue chairs red chairs 3,780 3,040 740. There are 740 more blue chairs.

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