# Unit 1 learning overview

You can use this overview to inform your planning and help secure children's learning of the mathematics covered in the unit. It includes reading, writing and ordering numbers with four digits, comparing and ordering positive and negative numbers, multiplying and dividing numbers up to 1000 by 10 and 100, and solving problems involving money and addition and subtraction.

Children read, write and order numbers with four digits. They partition them into multiples of 1000, 100, 10 and 1 and understand the importance of zero as a place-holder in numbers such as 2036. They use their understanding of place value to add or subtract 1, 10, 100 or 1000 to or from whole numbers, responding to questions such as:

• 'What needs to be added/subtracted to change 4782 to 9782? Or 2634 to 2034?'
• 'What is 100 ml more/less than 3250 ml? What is 10 m more/less than 5000 m?'
• 'Which is less: 4 hundreds or 4 tens?'

Children recognise and interpret negative numbers on the number line and in practical contexts, and use this knowledge to solve problems. For example, they read positive and negative numbers representing temperatures on a thermometer. They compare temperatures from different places around the world, or from their work in science, and can say which are warmer or colder. They compare and order positive and negative numbers, and position them on a number line, for example, to identify temperatures that are higher than 9°C but lower than 6°C. They use the < and > signs to record statements such as $-3<-1$ or $-1>-3$. They solve problems such as: 'The temperature is 2°C. How much must it rise to reach 3°C?'

Children count forwards and backwards in steps of equal sizes, starting from a positive or negative number. They count back in fours from 40 and discuss what happens when they reach 0. They predict numbers that will occur in the sequence, using their counting skills to answer questions such as: If I keep on subtracting 3 from 10, will 13 be in my sequence? They use a calculator to check, recognising how negative numbers appear in the display.

Children multiply and divide numbers up to 1000 by 10 and then 100. They understand and can explain that when a number is divided by 100 the digits of the number move two places to the right and when a number is multiplied by 100 the digits move two digits to the left. They use a calculator to investigate whether dividing by 10 and then 10 again has the same effect as dividing by 100. They apply their knowledge of multiplying and dividing by 10 and 100 to solve problems involving scaling, such as: 'A giant is 100 times bigger than you. How wide is the giant's hand span? How long is the giant's foot?' They extend their knowledge of multiplication and division facts to 10 × 10 and use this knowledge and their understanding of place value to begin to multiply and divide multiples of 10 such as $50×6$, $90×3$, $80÷4$, $150÷3$.

Children add and subtract pairs of two-digit numbers by drawing on their knowledge of place value and number facts. They identify when to use mental strategies such as partitioning or rounding and adjusting. They recognise that $49+37$ is equivalent to $50+37-1$, or that $98-43$ can be calculated as $98-40-3$. They record the steps of a mental calculation, for example on an empty number line, and compare their approach with the approaches used by others.

Children solve problems, including those involving money. They identify what calculations to do, when to calculate mentally (with or without jottings) and when to use a calculator. They learn how to clear a calculator display before starting a calculation and how to correct an accidental wrong entry with the clear-entry key. They learn also how to enter money and how to interpret the display in the context of the question. For example, to calculate $\mathrm{£}4.35+\mathrm{£}3.85$ they key in $4.35\left[+\right]3.85\left[=\right]$ and interpret the outcome of 8.2 as £8.20. They write down the keys pressed as a record of their method.

Children solve puzzles involving addition and subtraction. For example, they use numbers 37, 52, 77 and 87 to satisfy statements such as $\square -○=35$, or $\square +○=114$.

Children contribute to paired, grouped and whole-class discussions about their calculation strategies. They listen to others' explanations and ask questions if they need clarification. They explain their solutions in writing, recording the stages in the problem in a systematic way.