I need something explained from the Singapore 1A HIG.

[snickelfritz]

Can I put on my best valley girl accent and say "I don't get it!"?

 

We're doing Unit 6, subtracting from a 2 digit number by subtracting from a 10. Pg. 74 of the HIG.

 

They ask you to write some problems in the following format, and ask your student to fill in the blanks:

 

13-6=______ +3

14-7=3+________

 

I can fill in the blanks and figure out what the number should be. I don't see the point or what I'm supposed to be explaining. Then, on the mental math, they have problems like:

12-10=0+______

 

Those are on Mental math 17, pg. a7.

[Snickerdoodle]

Explain like this:

 

13-6=______ +3

 

is the same as ( 10 +3 ) -6. First you subtract the 6 from the 10 and add it to the 3.

 

 

14-7=3+________

 

is the same as (10 + 4) -7. First you subtract the 7 from the 10 and obtain 3. Add the 3 to the 4.

 

 

Does this help?

[Snickerdoodle]

 

I look at it as a strategy (one of many). Sometimes the strategy works out, sometimes another strategy works better.

 

That's what I like about the program we are using now. It says: solve by any convenient method.

[snickelfritz]

That does make sense, thank you both.