Section A: Practice Problems Count to Add and Subtract

Section Summary

Details

In this section, we counted two groups of things to figure out how many there are altogether.

Counters. Yellow, 3. Red, 4.

3 yellow counters and 4 red counters is 7 counters.

3 and 4 is 7.

We added more things and found out how many there were altogether.

5 frame full. Below, 4 counters.

There were 5 counters on the 5-frame and we added 4 more counters.

5 and 4 is 9.

We subtracted, or took away, some things and figured out how many were left.

5 frame, 3 counters.

There were 5 counters on the 5-frame and we took away 2 of them.

5 take away 2 is 3.

Problem 1 (Lesson 2)

Green and orange pattern blocks.

There are squares.

There are triangles.

There are shapes.

Problem 2 (Lesson 3)

  1. Orange pattern blocks. Green pattern blocks.

    There are shapes.

  2. Orange pattern blocks.

    There are squares.

  3. Green pattern blocks.

    There are triangles.

Problem 3 (Lesson 4)

  1. Count out 4 counters.
    Add 1 more.

    There are counters.

  2. Count out 6 counters.
    Add 1 more.

    There are counters.

  3. Count out 8 counters.
    Add 1 more.

    There are counters.

Problem 4 (Lesson 5)

  1. Count out 8 counters.
    Take away 2 counters.

    There are counters.

  2. Count out 6 counters.
    Take away 2 counters.

    There are counters.

  3. Count out 4 counters.
    Take away 2 counters.

    There are counters.

Problem 5 (Exploration)

Start with a full 5-frame.

Player 1 rolls a cube on the number mat and takes away or adds that number of counters while player 2 is not looking.

Then player 2 figures out what player 1 did.

Players take turns switching roles.

Problem 6 (Exploration)

Roll a cube onto a number mat.
Count out that number of counters.

Roll a cube again onto the number mat.
Count out that number of counters.
How many counters do you have in all?

Problem 7 (Exploration)

Pick a number from the list to put in the blank space.

2

7

6

3

Then try the problem you made.

  1. Count out 8 counters.
    Take away counters.
    How many counters are left?

  2. After you try the problem you made, try it again with a different number in the blank space.
    Do you think your answer will be the same or different?
    Explain.