Number Riddles
Estimation
Exponential Notation
Conversion
Multiplication and Division
100
I have 4 digits. My 7 is worth 7*1,000. My 2 is worth 200. One of my 4s is worth 40. The other is worth 1/10 as much. What number am I?
What is 7,244
100
Write an expression to estimate the quotient of 962/25.
What is 1000/25 = 40?
100
Write 10^2 in standard notation.
What is 100?
100
This is the number of ounces in 1 pound.
What is 16?
100
16*2
What is 32?
200
I have five digits. My 9 is worth 9*10,000. My 2 is worth 2 thousand. One of my 7s is worth 70. The other is worth 10 times as much. My other digit is a six. What number am I?
What is 92,776?
200
Write an expression to estimate the product of 48 * 13.
What is 50 *10 = 500?
200
Write 1,000 in exponential notation.
What is 10^3?
200
This is the number of ounces in 5 pounds.
What is 80?
200
364*9
What is 3,276?
300
I have 5 digits. My 5 is worth 50,000. My 8 is worth 8,000. One of my 6s is worth 60. The other is worth 10 times as much. My other digit is 0. What number am I?
What is 58,660?
300
Write an expression to estimate the quotient for 806/4?
What is 800/4=200?
300
Write 10*10*10*10*10 in exponential notation.
What is 10^5?
300
This is the number of ounces in 8 pounds.
What is 128?
300
806/4
What is 201 R 2?
400
I am a five digit number. My 3 is worth 3*10,000. My 4 is worth 4,000. One of my 2s is worth 20. The other 2 is worth 10 times as much. My other digit is 7. What number am I?
What is 34,227?
400
Write an expression to estimate the product of 364 * 9.
What is 400 *9=3600?
400
Write 624 *10^4 in standard notation.
What is 6,240,000?
400
This is the number of ounces in 10 pounds.
What is 160?
400
48*13
What is 624?
500
I am a six digit number. One of my 7s is worth 700,000. The other is worth 1/10 as much . My 8 is worth 8[100s]s. My 9 is worth 90. My other digits are 0. What number am I?
What is 770, 890?
500
Jesse collects cans for recycling. When he has 1500 cans the recycling center will pick them up from his house. Jesse has 120 bags with about 35 cans in each bag. Should he call the recycling center to arrange a pick up? Write an estimation expression to explain how you know.
What is 120 * 40 = 4800 and 4800 >1500? Also acceptable: What is 120 * 30 = 3600 and 3600 >1500?
500
Write 10^6 as a product of 10s.
What is 10*10*10*10*10*10?
500
Write an expression to with grouping symbols to model the number story. Then solve. Allen is shipping a gift to his cousin. The gift weighs 4 pounds. The box and shipping materials weigh 9 ounces. What is the total weight of the package in ounces?
What is (4*16) + 9 = 73 ounces?
500
962/25
What is 38 R 12?
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