Manipulative assignment
Tania Décaudin
Double sided counters.
Double-sided counters are very versatile and can be used in many different strands. The following are a few examples of how to use them in a classroom. Most of the examples are for the primary grades but can be easily adapted for older students.
Fractions
Ask students to lay out 9 red counters in rows of three. Ask students how many counters are there in total. Then ask them to turn over one row to the yellow side. How many have been turned over? Three ninths or one third (1/3) You can adapt this to any number.
Probability
Have students estimate the chances of the counter being red or yellow if you toss it 20 times. Ask students to toss the counter and record how many times the counter fell on yellow or red. Check their estimate.
Put 20 counters in a bag. Have students estimate the chances of picking more red or more yellow. In groups of 2 have them draw 10 times each, returning the counter to the bag after each draw. Have them record answers and then check their estimate.
Multiplication and Division
Have students make an array using counters. Have them add each row. 3+3+3=9 Or 3x3 =9. You can adapt this to any number.
Give students 12 counters. Tell the students at first to divide the counters into 3 equal groups and to write down the number statement. 12÷ 3=4. Then ask them to divide the counters into different groups that are equal until they have found all the different combinations. (extension: 24, 36, 48 etc..)
Addition and subtraction
Lay out 5 red counters and 2 yellow counters and add them together: 5+2=7. Underneath, lay out 2 yellow counters and 5 red counters and add them together: 2+5=7. Show the reciprocal addition. + = 7
Lay out 2 red counters and 3 red counters. Add them together. 2+3=5. Then have the students remove the 2 red counters. How many are left? 5-2=3. This activity can help clarify the relationship between the number families.
Equal to, greater than or less than
Place 2 red counters and 3 yellow counters on the desk. Next to it place 1 red counter and 4 yellow counters. Write down the number sentence. 2+3=5 and 1+4=5. Decide which statement is true and write down the appropriate symbol. ( = ≥ ≤)
Skip counting
Place 2 red counters next to 2 yellow counters and continue the pattern until there are 20 counters on the table. Then ask student to count by 2s.
Patterning with 2 attributes
Create 2 colour patterns with different combinations. (2 yellow, 1 red) (3 red, 2 yellow) etc…
Negative and positive numbers
Draw a line in the center of the paper. That line represents 0. Place the yellow counters to the left of the number and the red counters to the right of the 0. Numbers to the right (red) are positive numbers and numbers to the left (yellow) are negative numbers. It is a great way to visualize when adding and subtracting negative numbers.
Thermometers
Give students a large copy of a thermometer. Use the 2 coloured counters to show the difference of -3ºC and 5º. OºC is the line marking the change of colour.
Find the missing number
Grade 3
Objective: to find the missing term in a number sentence, think about related facts or think about the opposite operation.
Curriculum expectation: find the value of the missing term in a number sentence (3m25, 3m26, 3m31)
Students should be systematic to ensure they do not miss any pairs of numbers. Students should recognize that after 7+8, the number sentences repeat because when you add, order does not matter.
Materials: Counters, Addition chart
Mind’s on:
Write the number sentence 5 +3=8 on the board. Erase the 3. Ask: How could you find the missing number?
Introduce the game: How many are missing? Goal: to find how many counters are hidden.
You will need 18 counters.
· Take between 10 and 18 counters
· Put some counters in one hand and some in the other
· Tell your partner how many counters you have altogether.
· Show how many you have in one hand. Ask your partner how many you have in the other hand.
· What strategies did you use to find the missing number? Share your ideas to start a class list.
During:
While students are playing the game observe and listen. Questions to ask: How many counters do you see? How many counters in one hand?
How did you find how many counters were in your partner’s other hand. (possible answers: I counted on by 1s from 9 until I got to 14. She had 5 counters in her other hand.)
Have students write down some of their strategies as they are playing the game.
After:
Invite student volunteers to describe the strategies they used to find a missing number. Make a list of all the strategies on the chart paper. Show that no matter which strategy they us to find a missing number. They should always get the same answer. Display work on board for students to see and compare.
Source:
Taken from Math Makes Sense Unit 2 Lesson 5 Pages 68 and 69 of the teacher manual