Mental Math Strategies
1. Subtract 800, subtract 50, add 2.
2. Subtract 800, subtract 60, add 2.
3. Subtract 800, subtract 50, subtract 8.
4. Subtract 800, subtract 60, subtract 8.
3. What is subtract 800, subtract 50, subtract 8?
The estimation of the following numbers rounded to the nearest hundred.
1,232 + 949 + 756 = x
What is 1,200 + 900 + 800 = 2,900?
Find the sum.
1,232 + 949 + 756 = x
What is x = 2,937?
Find the difference.
7,000 - 3,290 = x
What is x = 3,710?
Use inverse to check if the following equation is true. Write yes or no.
40,700 - 23,984 = 17,716
What is no?
Find the sum.
26,425 + 5,436 = x
What is x = 31,861?
1,145 rounded to the nearest hundred.
What number makes the number sentence true?
3,050 + x = 3,050
What is 0?
Find the difference.
10,362 - 5,842 = x
What is 4,520?
Find the difference.
203,056 - 5,213 = x
Find the sum.
2,489 + 3,052 = x
What is x = 5,541?
1,096 rounded to the nearest hundred.
What is 1,100?
The property states that any number plus 0 equals zero.
What is identity property?
51,823 - 23,352 = x
What is x = 28,471?
Find the difference.
70,000 - 25,228 = x
What is x = 44,772?
Find the sum.
1,145 + 1,096 = x
What is x = 2,241?
1,316 rounded to the nearest hundred.
What is 1,300?
Find the sum.
28,814 + 32,097 = x
What is x = 60,911?
46,790 - 19,909 = x
What is x = 26,881?
Find the difference.
8,052 - 1,205 = x
What is x = 6,847?
Find the sum.
1,316 + 981 = x
What is x = 2,297?
981 rounded to the nearest hundred.
What is 1,000?
Find the sum.
28,378 + 3,333 = x
What is x = 31,711?
Find the difference.
2,297 - 2,241 = x
What is x = 56
Use inverse to check if the equation below is true. Write yes or no.
20,008 - 16,074 = 3,934
What is yes?