Step-by-step Maths Level 3: Measuring with a ruler and reading a scale
Part of the Step-by-step Maths Level 3 length and mass chapter. Chapter overview · whole chapter on one page
Measuring with a ruler and reading a scale
To measure with a ruler, put the 0 at the start of the line. Read the number where the line ends.
On a scale, find the label before the pointer, then count the small marks.
Key ideas
- Line up the 0 with the start.
- Read the end of the line.
- On a scale, count the small marks from the label.
Method. Use the ruler: find the start and the end of the line, then the difference.
- Put the 0 at the start of the line. Line up the ruler so the line begins at 0.0 cm
- Read where the line ends. The end of the line is on this number.The end is at 7
- Write the length. The length is the end number, because we started at 0.7 cm
Check. Count the centimetres from 0 to 7: 7 cm.
Watch out. Put the 0 of the ruler at the start of the line, then read the end.
Method. Use the ruler: find the start and the end of the line, then the difference.
- Find where the line starts. The line starts at this mark.start = 2 cm
- Find where the line ends. The line ends at this mark.end = 7 cm
- Subtract the start from the end. The length is the distance between the two marks.7 - 2 = 5
- Write the length. This is how long the line is.5 cm
Check. Add the length to the start: 2 + 5 = 7 cm.
Watch out. Put the 0 of the ruler at the start of the line, then read the end.
Method. Find the label before the pointer, then count the small marks.
- Find the labels on the scale. The labels show every 100 g.0 g, 100 g, 200 g
- Count the marks from the label before. Each small mark is 50 g.the pointer is 350 g
- Write the reading. This is what the scale shows.350 g
Check. 350 g is between two labels, halfway or on a label.
Watch out. Each small mark is 50 g. Count them carefully.
Watch out
Watch out. Do not start measuring at 1. Start at the 0 mark, or subtract the start from the end.
Exam tip
Grown-up tip. Use a real ruler and a book. Ask the child to measure things at home, and to say the length in cm.
Exercise 9B Practice: measuring and reading
Non-calculatorMethod. Use the ruler: find the start and the end of the line, then the difference.
- Find where the line starts. The line starts at this mark.start = 5 cm
- Find where the line ends. The line ends at this mark.end = 11 cm
- Subtract the start from the end. The length is the distance between the two marks.11 - 5 = 6
- Write the length. This is how long the line is.6 cm
Check. Add the length to the start: 5 + 6 = 11 cm.
Watch out. Put the 0 of the ruler at the start of the line, then read the end.
Method. Use the ruler: find the start and the end of the line, then the difference.
- Put the 0 at the start of the line. Line up the ruler so the line begins at 0.0 cm
- Read where the line ends. The end of the line is on this number.The end is at 12
- Write the length. The length is the end number, because we started at 0.12 cm
Check. Count the centimetres from 0 to 12: 12 cm.
Watch out. Put the 0 of the ruler at the start of the line, then read the end.
Method. Use the ruler: find the start and the end of the line, then the difference.
- Find where the line starts. The line starts at this mark.start = 3 cm
- Find where the line ends. The line ends at this mark.end = 8 cm
- Subtract the start from the end. The length is the distance between the two marks.8 - 3 = 5
- Write the length. This is how long the line is.5 cm
Check. Add the length to the start: 3 + 5 = 8 cm.
Watch out. Put the 0 of the ruler at the start of the line, then read the end.
Method. Use the ruler: find the start and the end of the line, then the difference.
- Find where the line starts. The line starts at this mark.start = 6 cm
- Find where the line ends. The line ends at this mark.end = 9 cm
- Subtract the start from the end. The length is the distance between the two marks.9 - 6 = 3
- Write the length. This is how long the line is.3 cm
Check. Add the length to the start: 6 + 3 = 9 cm.
Watch out. Put the 0 of the ruler at the start of the line, then read the end.
Method. Use the ruler: find the start and the end of the line, then the difference.
- Find where the line starts. The line starts at this mark.start = 1 cm
- Find where the line ends. The line ends at this mark.end = 4 cm
- Subtract the start from the end. The length is the distance between the two marks.4 - 1 = 3
- Write the length. This is how long the line is.3 cm
Check. Add the length to the start: 1 + 3 = 4 cm.
Watch out. Put the 0 of the ruler at the start of the line, then read the end.
Method. Use the ruler: find the start and the end of the line, then the difference.
- Find where the line starts. The line starts at this mark.start = 1 cm
- Find where the line ends. The line ends at this mark.end = 5 cm
- Subtract the start from the end. The length is the distance between the two marks.5 - 1 = 4
- Write the length. This is how long the line is.4 cm
Check. Add the length to the start: 1 + 4 = 5 cm.
Watch out. Put the 0 of the ruler at the start of the line, then read the end.
Method. Use the ruler: find the start and the end of the line, then the difference.
- Put the 0 at the start of the line. Line up the ruler so the line begins at 0.0 cm
- Read where the line ends. The end of the line is on this number.The end is at 4
- Write the length. The length is the end number, because we started at 0.4 cm
Check. Count the centimetres from 0 to 4: 4 cm.
Watch out. Put the 0 of the ruler at the start of the line, then read the end.
Method. Use the ruler: find the start and the end of the line, then the difference.
- Put the 0 at the start of the line. Line up the ruler so the line begins at 0.0 cm
- Read where the line ends. The end of the line is on this number.The end is at 5
- Write the length. The length is the end number, because we started at 0.5 cm
Check. Count the centimetres from 0 to 5: 5 cm.
Watch out. Put the 0 of the ruler at the start of the line, then read the end.
Method. Find the label before the pointer, then count the small marks.
- Find the labels on the scale. The labels show every 100 g.0 g, 100 g, 200 g
- Count the marks from the label before. Each small mark is 50 g.the pointer is 100 g
- Write the reading. This is what the scale shows.100 g
Check. 100 g is between two labels, halfway or on a label.
Watch out. Each small mark is 50 g. Count them carefully.
Method. Find the label before the pointer, then count the small marks.
- Find the labels on the scale. The labels show every 100 g.0 g, 100 g, 200 g
- Count the marks from the label before. Each small mark is 50 g.the pointer is 400 g
- Write the reading. This is what the scale shows.400 g
Check. 400 g is between two labels, halfway or on a label.
Watch out. Each small mark is 50 g. Count them carefully.
Method. Find the label before the pointer, then count the small marks.
- Find the labels on the scale. The labels show every 100 g.0 g, 100 g, 200 g
- Count the marks from the label before. Each small mark is 50 g.the pointer is 250 g
- Write the reading. This is what the scale shows.250 g
Check. 250 g is between two labels, halfway or on a label.
Watch out. Each small mark is 50 g. Count them carefully.
Method. Find the label before the pointer, then count the small marks.
- Find the labels on the scale. The labels show every 100 g.0 g, 100 g, 200 g
- Count the marks from the label before. Each small mark is 50 g.the pointer is 450 g
- Write the reading. This is what the scale shows.450 g
Check. 450 g is between two labels, halfway or on a label.
Watch out. Each small mark is 50 g. Count them carefully.
Method. Find the label before the pointer, then count the small marks.
- Find the labels on the scale. The labels show every 100 g.0 g, 100 g, 200 g
- Count the marks from the label before. Each small mark is 50 g.the pointer is 850 g
- Write the reading. This is what the scale shows.850 g
Check. 850 g is between two labels, halfway or on a label.
Watch out. Each small mark is 50 g. Count them carefully.
Method. Find the label before the pointer, then count the small marks.
- Find the labels on the scale. The labels show every 100 g.0 g, 100 g, 200 g
- Count the marks from the label before. Each small mark is 50 g.the pointer is 750 g
- Write the reading. This is what the scale shows.750 g
Check. 750 g is between two labels, halfway or on a label.
Watch out. Each small mark is 50 g. Count them carefully.
Method. Find the label before the pointer, then count the small marks.
- Find the labels on the scale. The labels show every 100 g.0 g, 100 g, 200 g
- Count the marks from the label before. Each small mark is 50 g.the pointer is 500 g
- Write the reading. This is what the scale shows.500 g
Check. 500 g is between two labels, halfway or on a label.
Watch out. Each small mark is 50 g. Count them carefully.
Method. Find the label before the pointer, then count the small marks.
- Find the labels on the scale. The labels show every 100 g.0 g, 100 g, 200 g
- Count the marks from the label before. Each small mark is 50 g.the pointer is 700 g
- Write the reading. This is what the scale shows.700 g
Check. 700 g is between two labels, halfway or on a label.
Watch out. Each small mark is 50 g. Count them carefully.