## Tuesday, September 22, 2009

### Math problems of the week: 3rd grade Investigations (TERC) vs. Singapore Math

I. From the second 3rd grade Investigations homework assignment (Unit 1, Session 2.1, "Trading Stickers, Combining Coins", p. 38):

Which addition combinations are you practicing?

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2. Write two addition combinations that are hard for you, and explain what helps you remember them.
What helps me:
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What helps me:
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II. From the second 3rd grade Singapore Math exercise (Primary Mathematics 3A Standards Edition, Unit 1, "Numbers 10-10,000", p. 11):

Write the missing numbers:

(a) 999 = 900 + ____ + 9
(b) 2658 = 2000 + 600 + 50 + ____
(c) 4955 = 4000 + 900 + ____ + 5
(d) 1773 = 1000 + ____ + 70 + 3
(e) 3332 = ____ + 300 + 30 + 2
(f) 5690 = 5000 + ____ + 90
(g) 6206 = 6000 + ____+ 6

III. Extra Credit:
Consider a third grader child who isn't practicing any particular addition combinations because he or she has been after-schooled using the Singapore Math curriculum, and thus has mastered all addition combinations worth remembering, as well as the standard algorithm for adding arbitrary numbers. How is he or she to complete the Investigations problem set above?