Calculations

24-29 Understanding addition and subtraction

Extend understanding of the operations of addition and subtraction. Use and begin to read the related vocabulary.Use the +, - and = signs to record mental additions and subtractions in a number sentence, and recognise the use of a symbol such as n or s to stand for an unknown number.Recognise that addition can be done in any order, but not subtraction: for example, 3 + 21 = 21 + 3, but 21 - 3 3 - 21. (p.25-29)	Missing number algorithm Level 2: Allows fun addition game involving doubles and single numbers to calculate addition statements	Grid ClubNumber Cruncher Level One BBC Numbertime ‘Dartboard'
Understand that more than two numbers can be added. Begin to add three single-digit numbers mentally (totals up to about 20) or three two-digit numbers with the help of apparatus (totals up to 100). (p.27)

30-31 Rapid recall of addition and subtraction facts

Know by heart: all addition and subtraction facts for each number to at least 10; all pairs of numbers with a total of 20 (e.g. 13 + 7, 6 + 14); all pairs of multiples of 10 with a total of 100 (e.g. 30 + 70). (p.31)

Number bonds - to 5, 10, 100 or set your own. Ambleside: NumberBond Machines Similar to a Target Board, finding pairs of numbers totalling given number PrimaryGames Speed Grid Challenge Supports the teaching of number, allows comparison of two numbers in a visual manner Standards Site ITP ‘Difference'

32-41 Mental calculation strategies (+ and -)

Use knowledge that addition can be done in any order to do mental calculations more efficiently. For example: put the larger number first and count on in tens or ones; add three small numbers by putting the largest number firstand/or find a pair totalling 10; partition into '5 and a bit' when adding 6, 7, 8 or 9, then recombine (e.g. 16 + 8 = 15 + 1 + 5 + 3 = 20 + 4 = 24); partition additions into tens and units, then recombine. (p.33)	Interactive snakes and ladders game. One player option allows use with whole class. Great opportunity for effective questioning. Game 2: Screen showing 10 butterflies, x fly away, how many remain. Grid partitioned into five and a bit Game 3: Domino showing five plus x to make a total	BBC Numbertime ‘Snakes and Ladders' Count Me In Game 2 Game 3
Find a small difference by counting up from the smaller to the larger number (e.g. 42 - 39). (p.33)	Interactive numberline, changeable min/max, illustrates finding the difference of two numbers both on the number line and also through algorithm Comparison of numbers through counters then an animation to reflect the comparison of these numbers on a number line	Standards Site ITP ‘Number Line'     Standards Site ITP ‘Difference'
Identify near doubles, using doubles already known(e.g. 8 + 9, 40 + 41). (p.33)
Add/subtract 9 or 11: add/subtract 10 and adjust by 1.Begin to add/subtract 19 or 21: add/subtract 20 and adjust by 1. (p.35)	Interactive number square, allows change of number of columns and start number	Standards Site ITP ‘Number Grid'
Use patterns of similar calculations. (p.35)
State the subtraction corresponding to a given addition, and vice versa. (p.35)
Use known number facts and place value to add/subtract mentally. (p.37,39)
Bridge through 10 or 20, then adjust. (p.41)

46-51 Understanding multiplication and division

Understand the operation of multiplication as repeated addition or as describing an array, and begin to understand division as grouping (repeated subtraction) or sharing.Use and begin to read the related vocabulary. Use the ×, ÷ and = signs to record mental calculations in a number sentence, and recognise the use of a symbol such as n or s to stand for an unknown number. (p.47,49)	Excellent modelling of division through grouping. Through effective questioning can model process form physically sorting objects to informal recording of grouping on a number line. Game 4: Children calculate total number of counters from partially covered array of counters	Standards Site Grouping Count Me In Game 4: Arrays
Know and use halving as the inverse of doubling. (p.47,49)	Interactive function machine	From the turquoise box or from: Turquoise Box ‘Function Machine'

52-53 Rapid recall of multiplication and division facts

Know by heart:multiplication facts for the 2 and 10 times-tables; doubles of all number to 10 and the corresponding halves. Begin to know:multiplication facts for the 5 times-table. (p.53)	Fun activity to find doubles of numbers up to 10	BBC Numbertime ‘Dartboard'
Derive quickly: division facts corresponding to the 2 and 10 times-tables; doubles of all numbers to at least 15 (e.g. 11 + 11 or 11 × 2); doubles of multiples of 5 to 50 (e.g. 20 × 2 or 35 × 2); halves of multiples of 10 to 100 (e.g. half of 70). (p.53)

54-57 Mental calulation strategies (mult and div)

Use known number facts and place value to carry out mentally simple multiplications and divisions. (p.57)

58-59 Checking results of calculations

Repeat addition in a different order. (p.59)
Check with an equivalent calculation. (p.59)

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