MATH

It is very important that students continue to develop their number concepts with large numbers.  In preschool, kindergarten, and first grade, students worked on developing:

1)      a sense of quantity for the numbers 0-100;

2)    the concept that numbers can be shown as parts (6 can be a group of 2 and a group of 4 OR a group of 1 and a group of 5 OR 2 groups of 3);

3)    an understanding of the difference between counting groups and counting the objects in the groups.  Ex.:  “I have 3 groups of 5 and that’s the same as 15 objects.”

In second grade we build on these concepts and continue developing their number concepts of hundreds, tens, and ones.  Using these strategies is effective, efficient (once it becomes “mental math”), AND supports their continued development in number concepts.  

PARTIAL SUM STRATEGIES FOR ADDING 2-DIGIT NUMBERS:

·        Break the numbers into tens and ones, then first add the tens together and second add the ones together, and finally add those partial sums together. 

·        Break the numbers into tens and ones, then first add the ones together and second add the tens together, and finally add those partial sums together.

·        Break the smaller of the 2-digit numbers into tens and ones, then add the tens to the larger of the 2-digit numbers, and finally add the ones.