We did another organizing activity supporting the development of place value, unitizing chunks of ten, and trading up (regrouping). We each counted out a portion of my big jar of pop sticks, making bundles of tens and ones. We then added our quantities to that of our classmates, eventually finding the total number of pop sticks. This physical activity lends itself to the strategy of splitting two-digit numbers by place value prior to adding by place value. We modeled this strategy with pop sticks, equations, and the splitting model.
This is a great strategy when regrouping is not necessary. We have other, more sophisticated strategies for when regrouping is required, such as “keep one addend whole
and add to a friendly number”. This week the game is “Five in a Row”. Your child brought home a
game sheet. The empty grid represents a blank hundred chart, starting with one in the upper left
and ending with 100 in the lower right corner.