Primary Maths Spelling Progress: Books A, B,C, D.

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1 Other resources from Mulberry Publications include: Number Facts: (3 workbooks) Multiplictation Division Addition and Subtraction The Maths Together series: (consisting of six levels): Start-Ups, 1 and 2, 3, 4, 5, 6. The Maths Zone series: 8 books for pupils learning maths with the Resource Teacher. Tangrams: MakeSure Maths Photocopiable book A new series of 8 learning workbooks covering the whole primary mathematics curriculum. Number & Counting Rhymes and Jingles. A photocopiable book for junior classes. Dictionary of Primary Maths Spelling Progress: Books A, B,C, D. Ruler: Also available: 30 cm wooden ruler. Florence Gavin Dice Mulberry Publications Drogheda, Co. Louth Get more details by visiting our website

2 Florence Gavin 1999 Second edition 2000 Second edition (revised) 2004 Reprinted 2010 Reprinted 2016 (revised) All rights reserved. No part of this publication may be reproduced without the written consent of the publisher. Published by Mulberry Publications, Drogheda, Co. Louth, Ireland. Printed in Ireland Mathematical Signs and Symbols + plus, positive minus, negative multiply divide ± plus or minus > greater than Mathematical Signs and Symbols pi, (approximately) º degree ºC degree at {} encloses elements pound Preface > not greater than i euro This dictionary explains all the mathematical terms that are likely to be encountered at primary level. The ability to understand the language of mathematics and express mathematical ideas is important from the beginning. Although some of the words at this level may seem simple and commonplace it is their very familiarity that can give rise to problems. Words when used in their mathematical sense have very precise meanings that may be different from their more familiar meanings. A clear grasp of these basic terms helps provide a solid foundation on which to build. While a rigorous approach to mathematical definitions is essential the emphasis here is on clarity and understanding and meanings are presented in a way that is interesting and stimulating as well as being accurate. < less than < not less than = equals not equal greater than or equal to less than or equal to square root union l ml mm cm m km mg g kg litre millilitre millimetre centimetre metre kilometre milligram gram kilogram The definitions in this dictionary are not intended to teach children new concepts in maths but to refine and consolidate ideas they already understand. An effective way to sharpen understanding of maths is to discuss it with others and to write about it. To do this you need to have a mathematical vocabulary. intersection element of not an element of cm 2 m 2 ha square centimetre square metre hectare There is truth in the old adage a picture paints a thousand words - so time spent studying the illustrations will be well rewarded. Enjoy your mathematics! % per cent relation m 3 cm 3 cubic metre cubic centimetre

3 page 80 year Unit of time. There are days in a year - the time it takes the earth to revolve around the sun. There are 365 days in a calendar year. Every fourth year we add the quarter days and put in an extra day in February making 366 days in a leap year. Z zero Also called nought. It means no quantity. It is written as 0. If you subtract a number from itself the result is zero. e.g. 5 5 = 0. When you add zero to a number the number stays the same. e.g = 26. When you multiply any number by zero the result is zero. Example: 26 0 = 0. Numbers to the right of zero on the number line are positive and numbers to the left of zero are negative. Weather forecasts often refer to sub zero temperatures. Sub zero means below zero. e.g. - 5º Celsius. As the temperature rises from below zero ice melts at 0º C. page 1 Words in italics are cross-referenced. You can look up any word in italics as a separate entry headword. A abacus A calculating device with beads sliding on wires. It is sometimes called a counting frame. Used for counting, addition and subtraction. The beads stand for units, tens and hundreds. The value of a bead depends on which wire it is on. The abacus here shows 375. To add 514 to it you would put 5 more beads on the hundreds wire, 1 more bead on the tens wire and 4 more beads on the units wire. acre A measure of land size. Fields and farms can be measured in acres. It is not part of the metric system. 1 acre is equal to 0.4 (approx.) of a hectare. There are (approx.) acres in 1 hectare. acute angle An angle less than 90º.

4 page 2 page 79 AD After Christ. e.g. The year AD 2003 means 2003 years after the birth of Christ. AD stands for the Latin Anno Domini. It means in the year of the Lord. addition Putting things together to find how many there are altogether. The symbol for addition is +. Example: = 5. Also written as: additive inverse A number that when you add it to a given number the result in zero. Example: The additive inverse of 6 is 6 since 6 + ( 6) = 0. Sometimes called opposite number. X xy coordinates Pair of numbers used to indicate the position of a point. The numbers tell us how far the point is from the x axis and the y axis. The first number of the pair tells you the distance from the y axis. The second number tells you the distance from the x axis. Example: The xy coordinates (6,4) tell us a point is 6 units from the y axis and 4 units form the x axis. adjacent Next to. Beside. e.g. If we consider the angle B in the right angled triangle ABC, the side AB is the adjacent side. (the other side of the angle B is called the hypotenuse). algebra Branch of mathematics that uses letters and symbols. The letters represent numbers. e.g. If a=2 and b=5 then 3a + 2b = 16. a.m. Before midday. Between midnight and midday. From Latin: ante meridiem. Y yard Unit of length. It is not part of the metric system. It is part of the Imperial System of units. There are 3 feet in one yard. A yard is slightly smaller than a metre. (see foot)

5 page 78 page 3 W week Unit of time. There are 7 days in a week. There are 52 weeks in a year. weight Measure of how heavy an object is. The metric unit of measurement of weight is the kilogram (kg). The imperial unit is the pound. Weight is the force of gravity on an object. If you were on the moon you would weigh less. amount Total value. Amount is a term that is used in simple interest calculations. When money is invested in a bank the value that it grows to is called the amount. The amount is equal to the principal plus the interest earned. The formula for calculating the amount is: A = P + P R T 100 where P = principal, T = time, R = rate and A = amount. analog clock An ordinary clock in which time is represented by the position of the hands on a dial. (you may also see it spelt as analogue ). angle It is a measure of the rotation between two lines that meet at a point. It is measured in degrees. whole number A number that does not have a fractional or decimal part. e.g. 1, 2, 3,... are whole numbers for example is not a whole number. width Measurement from side to side. In a rectangle the width is the lesser of its two dimensions. anticlockwise Movement in the opposite direction to the movement of the hands of the clock. arc A curve. e.g. part of a circumference.

6 page 4 page 77 are A unit of area. It is 100m 2. A garden 10m by 10m is 1 are in area. There are 100 ares in 1 hectare. (Note: Are rhymes with pair). area The size of a piece of land or ground. The size of the surface of a shape. The shape could be for example the top of a table, a floor or a field. Area is expressed in terms of square units. e.g. cm 2, m 2, km 2. Area of land is expressed in hectares. To get the area of a rectangle multiply its length by its width. arithmetic Branch of mathematics. Uses numbers to count, measure and calculate. ascending Going up. To list numbers in ascending order you put the lowest value number first, followed by the next lowest and so on. The highest value comes last. associative property If you are adding a few numbers together it does not matter what way you group them, your answer will be the same. Example: (3 + 6) + 4 gives you the same answer as 3 + (6 + 4). This is called the associative property of addition. You are not vertex Meeting point of lines that form an angle. In 3-D shapes the points at which the edges meet are called vertices. (The plural of vertex is vertices). A cube has 8 vertices. A vertex is often called a corner in everyday speech. vertical Upright. Perpendicular to the horizontal. The leaning tower at Pisa is not vertical. volume The volume of something is a measure of how much space it occupies. We usually measure solid volume and liquid volume in different units. Solid volume is measured in cubic units: m 3, cm 3, mm 3. The volume of a cuboid shape is: length width height. Example: If the dimensions of a cuboid are: length =3cm, width = 4cm and height = 6cm its volume is 3cm 4cm 6cm = 72cm 3. Liquid volume is measured in litres and millilitres. 1 litre of water occupies 1,000cm 3 of space. [Measure the space occupied by 1 litre of milk (use a ruler and empty milk carton)].

7 page 76 page 5 V value The worth of something. The equivalent of something. What we may substitute for something. Example: y has a value of 5 in the equation y + 4 = 9. We may substitute 5 in place of y. variable Can have different values. We use a letter to represent a variable in an equation. Suppose we are finding the area of circles of different sizes we use the formula r 2. Here the letter r stands for radius - a variable since the length of the radius is different in each. (Note that is a constant). Venn diagram Diagram that shows the relationship between sets. It uses rectangles and circles to show the sets. Named after the English mathematician John Venn ( ). required to remember the term associative property, just make sure you understand the principle. average We use average to give us a measure of a middle quantity that represents all the numbers in a group. It is greater than the smallest number and less than the largest number in the group. To find the average of a group of values we add all the values together and divide their total by the number of values in the group. Example: the average age of a group of four children aged 8, 9, 11, 12 is 10 since ( ) 4 = 10. Suppose the 9 year old is replaced by a 13 year old, the average age would become 11, since ( ) 4 = 11. Arithmetic mean is another term for average. axis In a coordinate system the axes are two reference lines we measure from. We call the vertical axis the y axis and the horizontal axis the x axis. The plural of axis is axes. (see xy cooordinates). The above diagram of members of a club shows that Tom and Joe have a cat; Jane, Paul and Kate have a dog; only Sue and Mark have a cat and a dog.

8 page 6 page 75 axis of rotation A line about which a shape rotates. The earth has an axis of rotation. axis of symmetry A line that divides a shape into two exactly matching halves.also called line of symmetry. B bar chart Graph with horizontal or vertical bars used to represent values. Example: unitary method Method used to solve problems where the solution is based on finding the value of a single (unit) item. Example: If five bananas cost 80 cent how much do six cost? The first step is to find the cost of 1 unit (i.e. 1 banana). 80 cent 5 = 16 cent. Therefore 6 bananas cost 16 cent 6 = 96 cent. unknown A value that you are asked to find. e.g. In a money problem you could be told the principal, time and rate and asked to find the interest. Here the interest is the unknown. universal set The set of all the elements under consideration. Sometimes it is represented by the capital letter U. Other symbols are also used to represent it (usually Greek letters). Do not confuse the letter U with the union symbol. Example: In the diagram below the rectangle represents the universal set. Here U is the set of all the children in a school. Set A is the set children in 3rd class and set B is the set of children with blue eyes. U

9 page 74 page 7 base (i) In geometry it is the line on which a shape stands U union of sets Includes all elements of two sets. The symbol for union is. If set A= {1, 2, 3} and set B = {3, 4, 5, 6} then A B = {1, 2, 3, 4, 5, 6}. Note that although set A contains three elements and set B contains four elements the union of set A and set B does not contain seven elements, it has six elements - you must not count the elements in the intersection twice. unit A single item. The number one. When you multiply a number by 1 the number stays the same. e.g = 24. Unit also means a standard quantity of measure. Other quantities are expressed in terms of the unit. Example: The unit of length is a metre. The width of a room might be 4 standard units or 4m. When considering the place value of numbers we refer to the column before the decimal point as the units column. base (ii) The ordinary system of numbers that we use has a base of 10. (See place value). We can show this with a rod abacus as follows. In this system we can count up to nine in the units position and we get the next number by putting 1 in the tens position and zero in the units position. If we use a different number base it means the values of the positions are different. e.g. In a number base 8 system the values of the positions are as follows: We can count up to 7 in the units position. To get the next number we put a 1 in the eights position and zero in the units position. The number shown below is The subscript 8 denotes the base.

10 page 8 page 73 BC Before Christ. Christ was born 2,000 years ago so therefore 5,000 years ago is 3,000 BC. billion A thousand millions. It is written as 1,000,000,000. Using an exponent we could write it as binary number system A number system with a base of 2. It is used in computers. It has only two digits 0 and 1. bisect Divide into two equal parts. Example: Divide the line AB into two equal parts. Using A as the centrepoint draw two arcs as in diagram. Similarly with B as centre draw two arcs. Draw a line joining the points where the arcs intersect. This line bisects AB. block graph Graph in which quantities are represented by blocks stacked vertically or horizontally. brackets ( ) Symbols used to group numbers. They tell us which part of an expression to calculate first. Example: = 16 but 6 (2 + 4) = 36. triangle A three sided plane shape. The sum of its angles is 180º. Area of triangle = 1 2base height triangular number A number that can be represented by a triangle of dots. Examples: 3, 6, 10. true Not false. e.g. The following are examples of true statements:- The sum of the angles in a triangle is 180º; a rectangle has 4 sides. twenty-four hour clock Time system that does not divide the day into a.m. and p.m. e.g. 16:15 is a quarter past four in the afternoon. twice Two times. Multiply by two. Double. two dimensional Flat shape that does not have depth. It has two dimensions length and breadth.