standard_description: Apply properties of operations as strategies to add and subtract. (Students need not use formal terms for these properties.) Examples: If 8 + 3 = 11 is known, then 3 + 8 = 11 is also known. (Commutative property of addition.) To add 2 + 6 + 4, the second two numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 = 12. (Associative property of addition.)
problem_activity: Solve.
a.   7 × 10 = _______
b.   100 × 7 = _______
c.   _______ = 7 × 1,000
d.   10 × 3 = _______
e.   1,000 × 30 = _______
f.   _______ = 10 × 30
g.   100 × 14 = _______
h.   _______ = 10 × 25
i.   54 × 1,000 = _______


aligns: no