Study Guide for Addition
October 27, 2014
Students should be able to solve problems involving these skills:
1. Addition Properties:
Commutative (order) Property: 5+3=3+5
Identity (zero) Property: 5+0=5
2. Fact Families:
5+7=12
12-5=7
7+5=12
12-7=5
3. Find a Rule: Each number in the top row is related to the number in the bottom row by a
rule.
The rule for this table is add 3.
In
Out
4
7
3
6
1
4
5
8
?
?
4. Estimating sums :
Round to the hundreds:
Round to the tens:
152
200
42
40
+138
100
+98
100
300
140
5. Adding two and three-digit numbers:
13
235
54
352
+28
+457
+38
+194
Remember to regroup from the ones place to the tens place, and from the tens place to the
hundreds place.