Growth Point 4

Addition and Subtraction Growth Points activities

The tasks listed on the following pages are rich tasks from various sources that may be used with multi-level groups or students who are working at a particular level.

4. Basic strategies (doubles, commutativity, adding 10, tens facts, other known facts)

Given an addition or subtraction problem, strategies such as doubles, commutativity, adding 10, tens facts and other known facts are evident.

Butterflies

Materials: Butterfly templates for each student, paint.

Activity: Explain to the students that the butterflies are the templates for a new type of chocolate biscuit. There has, however, been a fault at the factory and they have not been properly completed. The biscuits are supposed to have the same number of Smarties on both wings of the butterflies, but they only have them on one wing. Ask students, ‘How many Smarties are there on this biscuit? How many smarties should there be on this biscuit?’.

Students use the paint to add the Smarties to one half of the biscuits to determine the correct answer. Students then fold over the wings to transfer the markings, and check if their prediction is correct.

Discuss the concept of doubling with the students. Students make the doubles for the numbers between 1 and 10.

Related key ideas: Combining, part-part-whole.

Fingers and toes

Materials: None (but this is an activity that is recommended for the morning!)

Activity: Students remove shoes and socks, and count together the total number of fingers and toes in their group. Ask for suggested strategies to make the counting easier, such as counting by 2s, 5s or even 10s.

Related key ideas: Quantity, cardinality principle.

10-frame match up

Materials: Templates of 10-frames.

Activity: The aim of this activity is to reinforce the concept of commutativity. Cut the worksheet into separate 10-frames. Students must match the pairs that relate to a rule (e.g. 6 + 4 and 4 + 6). Note that students should only match frames with the same symbols.

Extension: Use the blank 10-frames to have students develop their own pairs to show commutativity.

Related key ideas: Combining, part-part-whole, commutative property.

Draw a game card

Materials: Game cards, calculator, three sets of cards numbered 1 to 10.

Activity: Shuffle the number cards and place face-down. Students take turns to draw a number card from the pile and also to draw a game card. They then give the correct answer to the game card question for their selected number. For instance, if a student draws number 3 and game card ‘Make to 10’, the answer required is 7.

Partner checks the correct response, with a calculator if necessary. For each correct response, the student scores one point. The first student to score 10 points is the winner.

Related key ideas: Combining, separation, part-part-whole, commutativity

Variation: Use number cards 10 to 20, with a second set of game cards (e.g. ‘half’, ‘subtract 10’, ‘add to 20’ and ‘subtract to 10’).

Add them up

Materials: None

Activity: The aim of this activity is to give students strategies to use when adding together groups of numbers. Give students strings of numbers to add (see suggestions below). Encourage them to visit a range of strategies (e.g. look for tens first, then doubles, and use the commutativity rule) before they begin adding the groups, so that they can find the most appropriate.

Add 4, 3, 6, 5, 8, 7, 2, 9

Pair up 4 and 6, 3 and 7, 8 and 2.

Three pairs of tens equals 30.

Then use the plus 5 + 10 = 15, but only have 5 + 9 therefore = 14.

30 + 14 = 44.

Use sets of numbers below as practice:

5, 3, 6, 4, 5, 8, 2, 1

4, 7, 6, 9, 2, 5, 7, 1

5, 8, 4, 2, 5, 9, 5, 3

8, 6, 3, 9, 4, 0, 2, 6

7, 1, 5, 3, 7, 8, 4, 6

Related key ideas: Combining, associative property.

Connect four again

Materials: Activity card, cards numbered 41 to 90, coin.

Activity: Students take turns to draw a card. They then toss the coin, and if it lands as heads, they add 10 to their card value, and if it lands as tails they subtract 10. Students colour the appropriate square on the grid.

The winner is the first student to colour four squares in a row, vertically, horizontally or diagonally.

Related key ideas: Combining, separation, partitioning.

Jack's magic beans

Materials: Golden lima beans (lima beans painted on one side with gold spray paint, or use double-sided counters instead of lima beans), a container with a lid that fits 10 lima beans inside, a large book that can be used as a screen.

Activity: A student is given the container with the 10 golden lima beans inside, and places a screen/divider so that the other players cannot see it. The student shakes the container and tips out the beans where the other students cannot see them. The student then says ‘I can see x golden beans, so how many white ones are there?’ The other students then work-out how many white beans there are on the table. The first student removes the screen so that they can check their answers.

Related key ideas: Part-part-whole, partitioning, properties of addition.

How many more?

Materials: Ten blank 10-frames, 20 counters (10 of each colour), dice, numeral cards (1 to 9).

Activity: One student rolls the dice and places that number of counters on their 10-frame, then says, ‘I have x blue counters on my frame. How many more to make 10?’. The next student adds their counters (of a different colour) to the frame and says ‘I am adding x red counters to the frame because x and x is the same as 10’. Students then record their findings in words, numbers and pictures.

Related key ideas: Part-part-whole, partitioning, properties of addition.

Making 10

Materials: Dice, paper/whiteboard.

Activity: Students draw-up a T-chart. On one side they write ‘Number rolled’ and on the other they write ‘Number to 10’. Students take turns rolling the dice and recording that number in the first column. They then need to work out how many more to make 10.

Related key ideas: Part-part-whole, partitioning, properties of addition.

Variation: Combinations to 20, 50, 100 and so on.

Throw down sticks

Materials: A collection of icy-pole sticks which have numbers written on each side to total 10. For instance, 0 and 10, 1 and 9, 2 and 8, 3 and 7, 4 and 6, 5 and 5.

Activity: Students grab a handful of the icy-pole sticks and throw them down on the table.

Ask, ‘What is the easiest way to count the total of these numbers?’. Students suggest strategies for how they will add them together. They make bundle sticks that make 10 and then count the leftovers, or they may use doubles, or repeated addition of the same number. Students record the number sentences that have been created and the total.

Related key ideas: Part-part-whole, partitioning, properties of addition.

Variation: Ask ‘What is the smallest number you could get with x sticks? The largest? Can you get the same total using different sticks? Prove it’.

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