Measuring mass was the first unit in Sydney's brand-new Singapore 1B workbook, and it was a good introduction for her, because it was new work, and yet well within her capabilities--a sense of mastery is VERY important to my younger daughter's feeling of well-being within her day, and the occasional misread word in her Bob book causes angst enough, good lord.
The workbook problems, which have the student record an object's mass in "units" using the illustrations, then make comparisons between heavier and lighter by recognizing the logical order of the numbers used, are all well and good, but definitely require plenty real-world work.
Time to bring out the REAL scale!
To do this daily activity, Sydney first learned how to calibrate our student-grade balance scale. Then she wandered around the house, choosing five different objects to compare. In the beginning, she'd only compare the two objects that she put on either side of the scale, writing the results as a complete sentence in her notebook (you can see our word bank there on the dry-erase board--"naughty chore button" may not make sense to you, because I may not have told you about my discipline system, which relies on "naughty" chores listed on pinback buttons and pulled at random from a paper bag).
Once Syd got adept at the simple comparisons, she moved on to ordering all five items that she collected each day, either from lightest to heaviest or heaviest to lightest, however the whim took her. This is a terrifically complicated mathematical exercise, since it requires her to repeatedly make those side-by-side comparisons, but also use that information to judge her next side-by-side comparison, and her next, etc. She checked her work by demonstrating it to me, then wrote the results in her notebook.
I'm glad that Sydney did the extra work ordering items, because the next Singapore 1B unit that she's on now is graphing, with more comparing values, and the addition of performing mathematical equations using those comparisons. It's another unit that's well within her capabilities, but depending on my observations of how easily she performs the computations, we may pause for a few days of subtraction flash cards before we hit up the unit after that.