Developing Place Value Skills
In the beginning of the first grade, students become familiar with the concept of place value, and later learn to implement it when adding and subtracting. The following aims to build students’ implementation skills, but if your student has trouble with the concept of place value, refer to the end of the Kindergarten → First Grade section.

Students must add
A) a twodigit number and a onedigit number (e.g. 95+2, 32+7) and
B) a twodigit number and a multiple of 10 (e.g. 67+20, 43+50) (sums should be less than 100)


First demonstrate with these virtual base ten blocks to refresh their memory

Then use long addition (shown below)

Students must understand that in adding twodigit numbers, they must add tens and tens, ones and ones; and sometimes it is necessary to compose a ten, (refer to the end of the Kindergarten → First Grade section), in which case they would have to “carry over” their left over ones.

Practice with your student:

Mentally finding 10 more or 10 less than a given two digit number without having to count (e.g. 10+64, 10+37, 88  10, etc.)

Mentally subtracting multiples of 10 in the range 1090 from multiples of 10 in the range 1090 (positive or zero differences) (e.g. 90  60, 20+30, etc.)

Try making a game out of this! You can simply time them and see how fast they can do it, or you can try something more elaborate.

If student feels comfortable, proceed to explore the above concepts and exercises into the hundreds place (e.g. 200+300, 400+12, 510+6, etc.