The document provides instructions and examples for solving subtraction problems using patterns. It shows that when subtracting numbers with the same number of zeros, the difference will have that same number of zeros. Students are asked to identify basic math facts embedded in larger subtraction problems, calculate the differences, and determine how many zeros to include in the difference based on the original numbers. Several practice problems are provided without solutions for students to work through.

1. © 2007 M. Tallman

2. The following pattern of subtraction is
related to a basic math fact: 13 - 6 = 7
13 - 6 = 7
130 - 60 = 70
1300 - 600 = 700
13,000 - 6,000 = 7,000
130,000 - 60,000 = 70,000
1,300,000 - 600,000 = 700,000
© 2007 M. Tallman

3. The following pattern of subtraction is
related to a basic math fact: 15 - 7 = 8
15 - 7 = 8
150 - 70 = 80
1,500 - 700 = 800
15,000 - 7,000 = 8,000
150,000 - 70,000 = 80,000
1,500,000 - 700,000 = 800,000
© 2007 M. Tallman

4. 1 2 1 2 1 2
500 - 400 = 100
Step 1: Step 2: Step 3: Step 4:
Find and “box” Find the How many Place the same
the basic difference of the zeros are in numbers of zeros
math fact. basic math fact. each number? in the difference.
© 2007 M. Tallman

5. 1 2 3 1 2 3
12, 000 - 5,000
1 2 3
= 7,000
Step 1: Step 2: Find Step 3: Step 4:
Find and “box” the difference of How many Place the same
the basic the basic math zeros are in numbers of zeros
math fact. fact. each number? in the difference.
© 2007 M. Tallman

6. 1 2 3 1 2 3
10,000 - 5,000
Tip Do not
Tip:: Do not 1 2 3
= 5,000
count the
count the
zeros in the
zeros in the
basic math
basic math
fact.
fact.
Step 1: Step 2: Find Step 3: Step 4:
Find and “box” the difference of How many Place the same
the basic the basic math zeros are in numbers of zeros
math fact. fact. each number? in the difference.
© 2007 M. Tallman

7. 1 2 3 4 1 2 3 4
200,000 - 90,000
1 2 3 4
Tip Do not
Tip:: Do not
= 110000
,
count the
count the
zeros in the
zeros in the
basic math
basic math
fact.
fact.
Step 1: Step 2: Find Step 3: Step 4:
Find and “box” the difference of How many Place the same
the basic math the basic math zeros are in numbers of zeros
fact. fact. each number? in the difference.
© 2007 M. Tallman

8. Use what you know about subtraction
patterns to solve for the unknown variable.
14 - c = 8 c = 6
e - 60 = 80 e = 140
1,400 - 600 = u u = 800
14,000 - v = 8,000 v = 6,000
140,000 - 60,000 = w w = 80,000
k - 600,000 = 800,000 k = 1,400,000
© 2007 M. Tallman

9. Use what you know about subtraction
patterns to solve for the unknown variable.
11 - 3 = d d = 8
110 - f = 80 f = 30
c - 300 = 800 c = 1,100
11,000 - q = 8,000 q = 3,000
110,000 - 30,000 = j j= 80,000
m - 300,000 = 800,000 m = 1,100,000
© 2007 M. Tallman

10. Subtract mentally.
1. 800 - 300
=
1. 500
2. 900 - 500
=
2. 400
3. 14,000 - 3. 9,000
5,000 =
4. 900,000 - 4. 600,000
300,000 =
5. 12,000 - 5. 7,000
5,000 =
6. 700,000 - 6. 100,000
7.
600,000 =
6,000 -
7. 2,000
4,000 =
© 2007 M. Tallman