## Thursday, April 14, 2011

### Math problems of the week: 4th grade Trailblazers vs. Singapore Math

 I. The final decimals problems in the 4th grade Math Trailblazers Discovery Assignment Book, "Using Decimals" chapter, (before two math games at the end of the chapter), pp. 153-154:

 II. The final decimals problems in the 4th grade Singapore Math Primary Mathematics 4B Workbook, "Decimals" chapter, (before two decimal rounding exercises at the end of the chapter), pp. 32-33:

 III. Extra Credit: a. What is your favorite version of base-ten shorthand? b. How long will it be before, following in Dan Meyer's footsteps, Traiblazers goes digital, Professor Peabody becomes an animated character, and his Hundredths Chart becomes an interactive game?

Anonymous said...

The semi-amusing thing is the use of the word "short hand" referring to a clunky graphical representation of numbers which can be succinctly written in decimal form.

FedUpMom said...

I don't understand "use base-10 shorthand to describe these numbers." The numbers are already expressed in base 10, aren't they? What does Trailblazers want to see as the "right" answer here?

Anonymous said...

The "base-10 shorthand" is the system of boxes for hundreds, lines for tens, dots for ones, and ... badly drawn cubes for thousands. Keep the numbers small enough, please, or you have to use badly drawn hyper-cubes, I guess.

Actually this is not shabby. I often use a simpler "shorthand" where I use one pebble for 1, two pebbles for 2, and 3 pebbles for "many".

Jennifer said...

What is that picto-gram writing? Couldn't they have adopted something less awkward from ancient Egyptian hieroglyphs or something?