Estimate to Nearest 100
239 + 403 =
200 + 400 = 600
1,807 - 1,299 =
2000 -1000 = 1000
12, 406 + 10,938 =
10,000 + 10,000 = 20,000
When ROUNDING a number, look ...
... to the neighbor to the RIGHT.
What is the ANSWER TO AN ADDITION problem?
Sum
836 + 555 =
800 + 600 = 1,400
4,674 + 1, 784 =
5,000 + 2,000 = 7,000
23,794 + 33,333 =
20,000 + 30,000 = 50,000
If the number is 4 or BELOW, ...
... LEAVE IT ALONE.
or
... LET IT GO.
What is the ANSWER TO A SUBTRACTION problem?
Difference
1,296 + 622 =
1,300 + 600 = 1,900
7,084 - 5,454 =
7,000 - 5,000 = 2,000
67,493 + 45,555 =
70,000 + 50,000 = 120,000
If it is 5 or ABOVE, ...
... GIVE IT A SHOVE!
What operation does ALTOGETHER mean in a word problem?
Addition
987 - 539 =
1,000 - 500 = 500
9,789 + 7605 =
10,000 + 8,000 = 18,000
76,000 + 59,000 =
80,000 + 60,000 = 140,000
When adding/subtracting two numbers with different place value amounts, always round ...
Ex: 7,463 - 869 =
... the HIGHEST PLACE VALUE BOTH NUMBERS SHARE
What is the ANSWER TO A MULTIPLICATION problem?
Product
4,395 - 244 =
4,400 -200 = 4,200
9,991 - 6,295 =
10,000 - 6,000 = 4,000
128,504 + 111,392 =
130,000 + 110,000 = 240,000
Estimating is...
... finding an answer that is close to the actual answer by rounding the same place value.
SPELL the answer to a DIVISION problem.