Students will be able to find missing factors when completing three digit addition problems.
- Invite students to sit in a circle.
- Tell the students that they will be tossing a bean bag to the person next to them as they skip count.
- Give the students a starting number such as 24 and a skip counting pattern, such as for them to add three.
- Invite students to add on three to the previous number before tossing the bean bag to the person next to them.
- Tell the students that they will be learning how to use addition to find missing factors in three digit numbers.
Explicit Instruction/Teacher modeling(5 minutes)
- Tell the students that a missing factor is an unknown number. It can be in a sequence of numbers or in an addition problem.
- Tell the students that they are going to make connections to skip counting and find missing factors in the middle of number sequences.
- Using a number pattern of choice with a blank in the middle (such as 326, 328, ____, 332, 334) show the students how you can analyze two numbers that are next to each other and determine the pattern. For example, 326 + 2 = 328 and 332 + 2 = 334, so 328 + 2 = 330. The missing factor is 330.
- Show the students how to use this pattern to find the missing link in the number sequence.
Guided Practice(10 minutes)
- Divide the students into small groups of three or four students each.
- Distribute one set of numbered index cards to each small group.
- Write the following sequence on the board and ask each group of students to place the cards in the following order: 225, 229, ____, 237, and 241.
- Ask the students to work together and figure out how much is added to each number to get the next number.
- Challenge the students to find the number that is the missing link.
- If needed, give the students additional number sequences to practice in a small group.
Independent working time(15 minutes)
- Ask the students to complete the Number Pattern Parachute worksheet.
- Invite students to use the Tidy Sum 1000 worksheet to play the game together.
- For students who have difficulty with the abstract concept of finding missing factors, invite students to create base ten drawings or to draw as they count on.
- Allow students to use base ten blocks to represent the abstract numbers.
- Invite students to create digital representations of finding the missing links (factors) such as creating a diagram or an electronic drawing that shows how factors in sequences are found.
- Distribute individual whiteboards and whiteboard markers to the students.
- Ask the students to complete the following sequence, finding the missing addition links on their whiteboards: 653, 658, 663, ___, 673, and 678.
Review and closing(5 minutes)
- Ask students to share how the strategy of finding missing links or factors is different from other addition strategies.
- Invite students to think, pair, share with their neighbors and then to share in a class discussion.