We can add groups of 10 by counting by tens on a Hundreds Chart.

1

• We can add groups of 10 by counting by tens on a
  Hundreds Chart.

Gr1-U14-L1
2

• When we add groups of 10 to 2-digit numbers, we
  start with the 2-digit number and count on by
  tens.

Gr1-U14-L2
3

• We can add 2-digit numbers using tens sticks and
  ones cubes.

Gr1-U14-L3
4

• When we add 2-digit numbers using tens sticks and
  ones cubes, we can record what we do by writing
  an addition number sentence.

Gr1-U14-L4
5

• When we need to solve a story problem that asks
  us to add 2-digit numbers, we can use tens sticks
  and ones cubes to find the total. We can record
  what we do by writing an addition number
  sentence. First we add the ones and then we add
  the tens.

Gr1-U14-L5
6

• We can subtract groups of 10 by counting back by
  tens on the Hundreds Chart.

Gr1-U14-L6
7

• When we subtract 2-digit numbers, we subtract the
  ones place first and record how many ones we have
  left. Then we subtract the tens place and record
  how many tens we have left.

Gr1-U14-L8
8

• When we need to solve a story problem that asks
  us to subtract 2-digit numbers, we can use tens
  sticks and ones cubes to find the answer. We can
  record what we do by writing a subtraction
  sentence. First we subtract the ones and the the
  tens.

Gr1-U14-L9
9

• When we solve story problems, first we read the
  story. Then we decide if we add or subtract.
  Next, we write a number sentence for the story,
  and then we solve the number sentence and label
  the answer.

Gr1-U14-L10