Hello! I am Pip. Numbers are built from places, and every digit has a job. Let us find out how.
Quick revision: Number and place value
Read with Pip, cover the examples, then have a go. Use your browser’s Print command to print this sheet or save it as a PDF. Answers stay off the printout.
Pip’s tip: Read the column, not just the digit. Compare decimals by lining up equal place values.
In 4,706, the 7 represents seven hundreds: 700.
Key facts
Each whole-number place is ten times the place to its right.
After the decimal point come tenths, hundredths and thousandths.
Trailing decimal zeros do not change a value. Leading zeros in a decimal can matter.
On a number line, numbers get larger towards the right, including negative numbers.
Worked example 1
What is the value of the digit 7 in 4,706?
The 7 is in the hundreds column: 7 × 100 = 700.
Answer: 700.
Your turn · Try before opening
What is the value of the digit 8 in 582,041?
Show answer and method
80,000. The 8 is in the ten-thousands column.
Which is greater: 0.6 or 0.58?
Show answer and method
0.6. Write 0.6 as 0.60; 60 hundredths is greater than 58 hundredths.
The place of a digit tells you its value. In 8,153,260 the 5 is in the ten thousands place, so it is worth 50,000. After the decimal point the places are tenths, hundredths and thousandths. Multiplying by 10 moves every digit one place to the left.
The ones column would be empty, so a 0 holds the place. 36 × 10 = 360. The digits moved; no zero was just stuck on.
Worked example
In 8,153,260, what is the value of the 5? In 8.153, what is the value of the 3?
Read the places from the right: ones 0, tens 6, hundreds 2, thousands 3, ten thousands 5, hundred thousands 1, millions 8.
The 5 is in the ten thousands place: 5 × 10,000 = 50,000.
In 8.153 the places after the point are tenths 1, hundredths 5, thousandths 3.
The 3 is in the thousandths place: 3 ÷ 1,000 = 0.003.
Answer: 50,000 and 0.003
Comparing, ordering and rounding
Skills: NPV-04, NPV-05
To compare numbers, count the digits first, then compare from the left. To round, find the place you are rounding to, then look at the digit just to its right. If it is 5 or more, round up. If not, stay the same.
So 3,468 rounded to the nearest 100 is 3,500.
Worked example
Put in order, smallest first: 4,305; 4,035; 4,350; 3,999. Then round 7,462 to the nearest 100.
3,999 starts with 3 thousands, so it is the smallest.
The rest all have 4 thousands. Compare hundreds: 0, 3, 3. So 4,035 is next.
4,305 and 4,350 both have 3 hundreds. Compare tens: 0 and 5. So 4,305 is before 4,350.
For 7,462 to the nearest 100, look at the tens digit: 6. It is 5 or more, so round up: 7,500.
Answer: 3,999; 4,035; 4,305; 4,350, and 7,500
Negative numbers and intervals across zero
Skills: NPV-06, NPV-07
Negative numbers are below zero. Picture a thermometer: the lower you go, the smaller the number. When you count or subtract and pass zero, keep going into the negatives. To find the gap between a negative and a positive number, go up to zero first, then on to the positive number, and add the two parts.
Going down the line, numbers get smaller. −8 is lower than −3.
Worked example
(a) Count on in steps of 6 from −15. Write the first five numbers. (b) How far is it from −6 to 9? (c) Find the number half way along the line from −10 to 6. (d) How many whole numbers lie on the line from −4 to 3, including both ends?
(a) −15, then −15 + 6 = −9, then −9 + 6 = −3, then −3 + 6 = 3 (we crossed zero), then 3 + 6 = 9.
(b) From −6 up to 0 is 6. From 0 on to 9 is 9. The gap is 6 + 9 = 15.
(c) The gap from −10 to 6 is 10 + 6 = 16. Half of 16 is 8. −10 + 8 = −2.
(d) List them: −4, −3, −2, −1, 0, 1, 2, 3. That is 4 negatives, zero and 3 positives: 4 + 1 + 3 = 8.
Answer: (a) −15, −9, −3, 3, 9 (b) 15 (c) −2 (d) 8
Roman numerals
Skills: NPV-08
Roman numerals use letters. Add the values from left to right. If a smaller letter comes before a bigger one, take it away instead (IV is 5 − 1 = 4). You never use the same letter more than three times in a row. Only these six pairs are used: IV, IX, XL, XC, CD, CM. For example 99 is XC + IX = XCIX (not IC).
I
V
X
L
C
D
M
1
5
10
50
100
500
1,000
Worked example
Write 449 in Roman numerals.
Split it up: 400 + 40 + 9.
400 is CD (500 − 100).
40 is XL (50 − 10).
9 is IX (10 − 1).
Join them: CD + XL + IX.
Answer: CDXLIX
Counting in steps and reading scales
Skills: NPV-09, NPV-10
To read a scale, do not guess that each mark is 1. Find two labelled numbers, work out the gap between them, and divide by the number of small gaps. Then you know what each mark is worth.
Between 60 and 80 there are 4 equal gaps, so each gap is (80 − 60) ÷ 4 = 5. The arrow is one small gap after 60, at 65.
Worked example
What number does the arrow show on the scale above? Then count in 25s from 150 for five numbers.
The labels are 60 and 80. The difference is 80 − 60 = 20.
There are 4 small gaps between them, so each gap is 20 ÷ 4 = 5.
The arrow is one gap after 60: 60 + 5 = 65.
Now count in 25s: 150, 150 + 25 = 175, 200, 225, 250.
Answer: 65, and 150, 175, 200, 225, 250
Worked examples across the levels
Level 1 is the easiest. Level 5 is a real challenge. Try each one yourself before you read the steps.
Level 1 (Year 3): one step
What is the value of the 6 in 563?
The digits are 5 hundreds, 6 tens, 3 ones.
6 tens = 60.
Answer: 60
Level 2 (Year 4): one or two steps
Write 2,000 + 300 + 5 as one number. What is 10 more?
2,000 + 300 + 5 = 2,305 (the tens column is empty, so it is a 0).
10 more than 2,305 is 2,315.
Answer: 2,305, then 2,315
Level 3 (Year 5): two steps
Round 2,449,712 to the nearest 100,000.
The hundred thousands digit is 4.
Look at the next digit, the ten thousands: it is 4. That is less than 5, so stay.
Replace the rest with zeros: 2,400,000 (two million four hundred thousand).
Answer: 2,400,000
Level 4 (exam standard): several steps or working backwards
At midnight it is −6°C. By 6 am it rises 4 degrees. By noon it rises 9 more. By 6 pm it falls 11. What is the temperature at 6 pm?
−6 + 4 = −2.
−2 + 9 = 7.
7 − 11 = −4.
Answer: −4°C
Level 5 (challenge): three to five steps
I am a 4-digit number. Rounded to the nearest 100 I am 6,500. Rounded to the nearest 10 I am 6,450. My digits add up to 17. What number am I?
Nearest 100 is 6,500, so I am from 6,450 to 6,549.
Nearest 10 is 6,450, so I am from 6,445 to 6,454. Both clues together: 6,450 to 6,454.