MENTAL ARITHMETIC

TO BE EFFECTIVE MENTAL ARITHMETIC SHOULD: Provide regular short sessions of 10 minutes each day. This is more valuable than infrequent lengthy ones. Provide regular short sessions of 10 minutes each day. This is more valuable than infrequent lengthy ones. Provide a variety of activities each week. Provide a variety of activities each week. Instruct, demonstrate, explain and illustrate ideas and skills. Instruct, demonstrate, explain and illustrate ideas and skills. Put the emphasis on discussion and on sharing the different strategies that children use to find answers. Put the emphasis on discussion and on sharing the different strategies that children use to find answers. Make connections with previous learning. Make connections with previous learning. Use correct terms and teach new vocabulary. Use correct terms and teach new vocabulary. Target individuals, or small groups, with particular questions. Target individuals, or small groups, with particular questions. Make sure sessions are non-threatening and pupils feel comfortable in each one. Make sure sessions are non-threatening and pupils feel comfortable in each one.

STRANDS of MENTAL MATHEMATICS

Mental Strategies - MS Teaching the most commonly used strategies for performing mental calculations. However, pupils may develop their other, equally valid, strategies. Teaching the most commonly used strategies for performing mental calculations. However, pupils may develop their other, equally valid, strategies.

- - Counting on or back in ones e.g (LEVEL 1), s e.g → 40 → 50, (LEVEL 2) - - 2s, 5s and 100s (Level 3) When adding count on in simple unitary fractions (LEVEL 4) ¼ ¼ ¼ e.g. 2 ½ + ¾ 2 ½ → 2 ¾ → 3 → 3 ¼ EXAMPLES - MS

When subtracting, count back in tenths (LEVEL 4) e.g. 7.8 – → 7.7 → 7.6 → 7.5 When adding or subtracting, count on or back in a combination of ones, tens, hundreds and thousands, tenths and hundredths (LEVEL 5) e.g – → 5800 → 6000 → 7000

EXAMPLES - MS - - Rearranging numbers to make calculations easier e.g is the same as (large amount first) (LEVEL 2) - - Rounding and adjusting: 83 – 35 = Looking for multiples of 10: Near Doubles

Understanding the Number System (UNS) Skills in mental mathematics should be developed in parallel with a sound understanding of our number system. This strand outlines the development of a sense of number and the interrelationship within number. Skills in mental mathematics should be developed in parallel with a sound understanding of our number system. This strand outlines the development of a sense of number and the interrelationship within number.

EXAMPLES - UNS Count orally, in ones, forwards and then backwards. Count individually, in groups and as a class (LEVEL 1) Count on and back in ones, twos, tens, fives from a given number (Level 2) Counting orally forwards and backwards in halves and quarters (LEVEL 3) Counting orally forwards and backwards in tenths between whole numbers and crossing over whole numbers (level 4) Using combinations (level 5) EXPLORING PATTERNS – multiplication patterns / counting patterns

EXAMPLES - UNS Recognising and writing numbers (word and number format) Understanding the position of numbers on a number line (before / after) Understand and use the effect of multiplying whole numbers by 10 and 100 Recognising numbers that can be divided by 10 and 100 Ordering Numbers – increasing / decreasing Appreciating the inverse relationship between operations : ADDITION and SUBTRACTION / MULTIPLICATION and DIVISION

Approximation and Estimation (AE) The skills of approximating and estimating are important in the application of mathematics to real-life situations. This strand is closely related to The skills of approximating and estimating are important in the application of mathematics to real-life situations. This strand is closely related to ‘Understanding the Number System’.

EXAMPLES - AE Having a feel for the size of a set of objects Approximating numbers to the nearest 10, 100, 1000 Estimating calculations as a means of checking

Quick Recall (QR) The quick recall of number facts is essential for efficient mental calculations. The quick recall of number facts is essential for efficient mental calculations.

EXAMPLES - QR Knowing doubles Addition and subtraction within 20 Multiplication / Division Facts Measures Shape and Space

Mental Calculations (MC) This strand presents calculations which pupils might be expected to carry out mentally as their skills develop. This strand presents calculations which pupils might be expected to carry out mentally as their skills develop.

EXAMPLES - MC Building number fact families within 5 / 10 (level 1) Adding / subtracting 1, 2 or 0 from any number (level 1) Find what must be added to a number to make 10 and then 20 (level 2) e.g. 6 and how many make and how many make 20 Find what must be added to any two-digit number to make the next higher multiple of 10 e.g. 26 and how many more make 30

EXAMPLES - MC Adding and subtracting single digit numbers to and from 2 digit numbers bridging the ten Add or subtract 100 or multiples of 100 to or from any 3-digit number e.g – Add or subtract any two 2-digit numbers within 100, bridging the 10 (LEVEL 4) e.g then bridging the Find the difference between pairs of 2 or 3-digit numbers which are close (Level 4) e.g. 484 – 475

ACTIVITY WALT – identify the characteristics associated with the different strands within Mental Arithmetic WALT – identify the characteristics associated with the different strands within Mental Arithmetic Top Tips: Top Tips: - Listen to the views and opinions of others when making your choices - Reach agreement through negotiation and compromise - Select, classify, compare and evaluate information - Look closely at the vocabulary