Mental Addition
Mental Subtraction
Vocabulary
Rounding
Front-end estimation
100
22 + 57 =
What is 79?
100
83 - 52 =
What is 31?
100
1,578 is 2,000 when rounded to the nearest ____________.
What is "thousand"?
100
145 rounded to the nearest ten =
What is 140?
100
Using front-end estimation, 214 becomes _________.
What is 200?
200
37 + 44 =
What is 81?
200
63 - 32 =
What is 31?
200
50 is 100 when ______________ to the nearest 100.
What is "rounded"?
200
When rounded to the nearest hundred, 850 is __________.
What is 900?
200
Using front-end estimation, 775 becomes ___________.
What is 700?
300
44 + 35 =
What is 79?
300
86 - 32 =
What is 53?
300
The _______________________ in a number is the digit with the greatest place value.
What is "leading-digit".
300
When rounded to the nearest hundred, 2,475 is _________.
What is 2,400?
300
Using front-end estimation, 999 becomes_________.
What is 900?
400
123 + 64 =
What is 187?
400
185 - 14 =
What is 171?
400
_____________________ uses the leading digit to estimate a sum or a difference.
What is "front-end estimation"?
400
When rounded to the nearest thousand, 7,550 is ________.
What is 8,000?
400
Using front-end estimation, 245 + 355 is estimated to be __________?
What is 500?
500
137 + 142 =
What is 279?
500
152 - 126 =
What is 26?
500
879 becomes 800 when using ______________________.
What is "front-end estimation"?
500
4,500 rounded to the nearest thousand is ________.
What is 5,000?
500
Using front-end estimation, 778 + 988 is estimated to be ______________.
What is 1,600?
M
e
n
u