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Year 2 Teaching Sequence xxx

By Clyde Scott,2014-07-01 18:12
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Year 2 Teaching Sequence xxx

Year 2 Teaching Sequence Spring 3 Pairs to 20, solving word problems (three days)

Prerequisites:

    ; Partition 20 into pairs (see autumn teaching sequence 3 and spring oral and mental starter bank 3)

    ; Use the = sign to represent equality (e.g. 6 + 4 = 7 + 3) (see autumn teaching sequence 3)

    ; Recognise the use of a symbol such as ? to represent an unknown (see autumn teaching sequence 3)

Overview of progression:

    Children revise partitioning pairs to 20 (using the 20 bead frame) and then record the corresponding addition and subtraction sentences.

They use ‘slidy’ box’ cards to reinforce the idea of an empty box in number sentences. ? and ? are used to stand for

    mystery numbers in number sentences. Children go on to solve word problems involving simple addition and subtraction.

    Note that the 20 bead frame image previously used in Year 2 has beads in two colours grouping in fives. This helps children to subitise (recognise numbers without counting). The arrangement of 20 in two rows can help children to see the link with pairs to 10, one colour for five, and one for numbers less than or equal to five.

    Note that the approach to solving word problems here is to focus on children imagining the whole problem rather than being misled by words such as ‘more than’ when finding a difference is needed rather than addition. They are encouraged to think

    what would be necessary to do with the numbers to solve the problem, for example do numbers need to be compared, combined, or one number increased by another? They then identify the operation and calculation necessary to find the numerical answer, before answering the problem itself. Allow lots of time for the discussion at each stage, the actual arithmetic should be a minor part of the session, and is therefore easier than might be in a lesson focused on calculation. ? Original teaching sequence copyright Hamilton Trust, who give permission for it to be adapted as wished by individual users. Y2 Maths TS3 Spr 3days

    Watch out for children who see that we can reverse additions and get the same answer and think this also applies to subtraction, e.g. 18 + 2 = 20; 2 + 18 = 20, so 20 18 = 2 and 18 20 = 2, rather than swapping the 18 and 2.

    Watch out for children who only understand the equal sign as ‘makes’ rather than a symbol of equality.

    Watch out for children who want you to read the problem and work out what calculation to do rather than realising that this is the aim of the sessions!

? Original teaching sequence copyright Hamilton Trust, who give permission for it to be adapted as wished by individual users. Y2 Maths TS3 Spr 3days

Objectives:

    ; Find all pairs with a total of 20 and record the corresponding addition and subtraction facts

    ; Recognise the use of a symbol such as ? to represent an unknown

    ; Imagine what action would be needed to solve a word problem and decide what calculation is necessary (addition or

    subtraction)

    Whole class Group activities Paired/indiv practice Resources Show children the 20 bead frame (two rows of Group of 4-5 children Children work in pairs to shuffle a ; 20 bead frame ten beads). How many beads are there on In advance prepare ‘slidy box’ cards: pack of 0-20 cards, take one and (two rows of

     Ask children to 15 + 5 = 20 and 20 5 = 15 on the back discuss what needs to be added ten beads with each bar? And altogether?

    close their eyes whilst you slide the last three 12 + 8 = 20 and 18 + 2 = 20 to it to make 20. They record the whiteboard) on the bottom row behind the whiteboard. 20 2 = 18 and 20 18 = 2 addition. They also discuss what ; ‘Slidy box’ Open your eyes. How many have I hidden? How 17 + 3 = 20 and 13 + 7 = 20 would be left if this number was cards as

    20 3 = 17 and 20 17 = 13 taken away from 20 and record opposite do you know? What colour are they? How many

    16 + 4 = 20 and 14 + 6 = 20 the subtraction. Repeat with at ; 20 bead were on the bottom row? What do you add to

    20 4 =-16 and 20 16 = 4 least five different cards. strings seven to make ten?

    Write 17 + = 20 on the whiteboard. What Ask children to close their eyes whilst Easier: Children use 20 beads ; 0-20 cards

     you pick up a ‘slidy box’ card and hide strings to help. number goes in the box?

    Write 20 - = 17 on the whiteboard. How What number is one of the numbers. Harder: Challenge children to

     Repeat hiding write as many addition and many did I hide? So what number goes in the hiding? How do you know?

     either of the first two numbers on related subtraction sentences box?

    Repeat sliding other numbers of beads from addition cards, and either of the using pairs to 20 as they can. the bottom bar behind the whiteboard and second two numbers on subtraction encouraging children to use their pairs to ten cards. Ask children to explain how they to work out the missing number. know what the hidden number is.

    Shuffle a pack of 0-20 cards. Take one. What

     do I need to add to this number to make 20?15 + - = 20 Show this on the bead frame and record the

    addition sentence. What if I took this number Easier: Use 20 bead strings to help.

     away from 20? What would I be left with?

    Show this on the bead frame and write the

    subtraction. Repeat.

    ? Original teaching sequence copyright Hamilton Trust, who give permission for it to be adapted as wished by individual users. Y2 Maths TS3 Spr 3days

Write ? + ? = 10 on the board. There are two Children find at least two pairs of Group of 4-5 children ; Activity sheet

    mystery numbers in number see resources) Show children this addition grid: (mystery numbers in this sentence. What could

    sentences (see resources). They they be? If square is 8, what would triangle ? + 7 was 1? So there are lots of then make up two of their own for be? What if square

    2 9 7 another pair to solve. possible answers.

    Write 10 + ? + ? = 16 on the board. Easier: Most sentences have only 5 12 10 What could the mystery numbers be now? How one mystery number. How do you think it works? Discuss