1. © 2007 M. Tallman

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

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

4. © 2007 M. Tallman 4 5 Step 1: Find and “box” the basic math fact. Step 2: Find the difference of the basic math fact. Step 3: How many zeros are in each number? Step 4: Place the same numbers of zeros in the difference. 1 00=-00 0 2 1 2 1 2 1 0

5. 0005, 12, 7 = -000 000, Step 1: Find and “box” the basic math fact. Step 2: Find the difference of the basic math fact. Step 3: How many zeros are in each number? Step 4: Place the same numbers of zeros in the difference. 2 3 1 2 3 1 2 3 1

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

7. © 2007 M. Tallman 0000 0,000 9 20 11 = -0,000 Step 1: Find and “box” the basic math fact. Step 2: Find the difference of the basic math fact. Step 3: How many zeros are in each number? Step 4: Place the same numbers of zeros in the difference., Tip: Do not count the zeros in the basic math fact. 2 3 1 2 3 1 2 3 1 4 4 4

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

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

10. © 2007 M. Tallman Subtract mentally. 1.800 - 300 = 2.900 - 500 = 3.14,000 - 5,000 = 4.900,000 - 300,000 = 5.12,000 - 5,000 = 6.700,000 - 600,000 = 7.6,000 - 4,000 = 1.500 2.400 3.9,000 4.600,000 5.7,000 6.100,000 7.2,000