Year 1: Counting to 100 on the 100 square
Part of the Year 1 numbers to 100 chapter. Chapter overview · whole chapter on one page · Download worksheet (PDF) · Answers (PDF)
Counting to 100 on the 100 square
We can count all the way to 100. The 100 square helps us see the numbers in order. It has ten rows, and each row has ten numbers. Read each row from left to right. When a row ends, the next number starts the next row.
You can start counting from any number. Count on to go up. Count back to go down. The purple box is 47. Put your finger on it and count on.
Key ideas
- The 100 square shows the numbers 1 to 100.
- Each row has ten numbers.
- Count on to go forwards. Count back to go backwards.
- When a row ends, the next number starts the next row.
Key words. To count on is to say the next numbers in order, one more each time.
Method. Start at 47. Say the next number each time, one at a time.
- Start at 47. Put your finger on the number you start from.Start: 47
- Say 4 numbers, one at a time. Each new number is one more than the one before.48, 49, 50, 51
- Write the numbers in order. Write each number you said.48, 49, 50, 51
Check. Count back from 51 to 47 with your finger. The same numbers come again. ✓
Watch out. Do not say 47 again. Start with the number after it.
Key words. To count back is to say the numbers before, one less each time.
Method. Start at 30. Say the number before it, then the one before that.
- Start at 30. Put your finger on the number you start from.Start: 30
- Say 4 numbers, going back. Each number is one less than the one before.29, 28, 27, 26
- Write the numbers in order. Write each number you said.29, 28, 27, 26
Check. Count on from 26 to 30 to check. The same numbers come again. ✓
Watch out. Do not say 30 again. Start with the number just before it.
Key words. After means one more. Before means one less.
Method. After means one more. Find 69 on the 100 square first.
- Find 69 on the 100 square. 69 is 6 tens and 9 ones.69 = 6 tens and 9 ones
- Move one step on. This number is at the end of a row. The next number starts the next row.69 + 1 = 70
- Write the answer. 70
Check. Count on one from 69 and you say 70. ✓
Watch out. Do not write 69 again. The answer is the next number.
Watch out
Watch out: after 69 comes 70. Do not write 610. The row ends at 69, so 70 starts the next row.
Exam tip
Grown-up tip. Print a 100 square, or draw one on paper. Ask your child to point with a finger as they count. Start at different numbers, such as 34 or 58, and count on and back.
Exercise 6A Counting to 100
Non-calculatorKey words. To count on is to say the next numbers in order, one more each time.
Method. Start at 14. Say the next number each time, one at a time.
- Start at 14. Put your finger on the number you start from.Start: 14
- Say 3 numbers, one at a time. Each new number is one more than the one before.15, 16, 17
- Write the numbers in order. Write each number you said.15, 16, 17
Check. Count back from 17 to 14 with your finger. The same numbers come again. ✓
Watch out. Do not say 14 again. Start with the number after it.
Key words. To count back is to say the numbers before, one less each time.
Method. Start at 30. Say the number before it, then the one before that.
- Start at 30. Put your finger on the number you start from.Start: 30
- Say 3 numbers, going back. Each number is one less than the one before.29, 28, 27
- Write the numbers in order. Write each number you said.29, 28, 27
Check. Count on from 27 to 30 to check. The same numbers come again. ✓
Watch out. Do not say 30 again. Start with the number just before it.
Key words. After means one more. Before means one less.
Method. After means one more. Find 49 on the 100 square first.
- Find 49 on the 100 square. 49 is 4 tens and 9 ones.49 = 4 tens and 9 ones
- Move one step on. This number is at the end of a row. The next number starts the next row.49 + 1 = 50
- Write the answer. 50
Check. Count on one from 49 and you say 50. ✓
Watch out. Do not write 49 again. The answer is the next number.
Key words. After means one more. Before means one less.
Method. Before means one less. Find 81 on the 100 square first.
- Find 81 on the 100 square. 81 is 8 tens and 1 one.81 = 8 tens and 1 one
- Move one step back. Before means one less. Move one step back.81 − 1 = 80
- Write the answer. 80
Check. Count back one from 81 and you say 80. ✓
Watch out. Do not write 81 again. The answer is the number just before.
Key words. To count on is to say the next numbers in order, one more each time.
Method. Start at 60. Say the next number each time, one at a time.
- Start at 60. Put your finger on the number you start from.Start: 60
- Say 5 numbers, one at a time. Each new number is one more than the one before.61, 62, 63, 64, 65
- Write the numbers in order. Write each number you said.61, 62, 63, 64, 65
Check. Count back from 65 to 60 with your finger. The same numbers come again. ✓
Watch out. Do not say 60 again. Start with the number after it.
Method. Each number is 1 more than the one before it.
- Look at the numbers around each gap. The numbers go up or down by the same amount each time.71, 72, ?, 74, ?, 76
- Work out each missing number. Use the number before the gap, and add 1.Gap 3: 72 + 1 = 73
Gap 5: 74 + 1 = 75 - Write the missing numbers. 73, 75
Check. Read the whole line again. Every number is 1 more than the one before. ✓
Watch out. Check the numbers after the gap too. They should still go on by the same amount.
Method. Use the numbers above and below each empty box. Going down one row adds 10.
- Look above and below each empty box. The number above is 10 less. The number below is 10 more.33: 23 above, 43 below
- Work out each missing number. The empty box is 10 more than the number above it.23 + 10 = 33
- Write the missing numbers. 33
Check. Check it: the number below each box is 10 more than the box. ✓
Watch out. Look up or down the column. Do not guess from the numbers next to the box.
Key words. To count back is to say the numbers before, one less each time.
Method. Start at 100. Say the number before it, then the one before that.
- Start at 100. Put your finger on the number you start from.Start: 100
- Say 5 numbers, going back. Each number is one less than the one before.99, 98, 97, 96, 95
- Write the numbers in order. Write each number you said.99, 98, 97, 96, 95
Check. Count on from 95 to 100 to check. The same numbers come again. ✓
Watch out. Do not say 100 again. Start with the number just before it.
Key words. After means one more. Before means one less.
Method. After means one more. Find 39 on the 100 square first.
- Find 39 on the 100 square. 39 is 3 tens and 9 ones.39 = 3 tens and 9 ones
- Move one step on. This number is at the end of a row. The next number starts the next row.39 + 1 = 40
- Write the answer. 40
Check. Count on one from 39 and you say 40. ✓
Watch out. Do not write 39 again. The answer is the next number.
Method. Count from 90 to 100, and count how many numbers you said.
- Count from 90 to 100. Say every number, including the first and the last.90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100
- Count how many numbers you said. Count each number in your list once.11 numbers
- Write the answer. 11
Check. Count on from 90 for 10 more numbers. You land on 100. ✓
Watch out. Remember to count 90 and 100 as well. They are both in the list.
Key words. To count on is to say the next numbers in order, one more each time.
Method. Start at 27. Say the next number each time, one at a time.
- Start at 27. Put your finger on the number you start from.Start: 27
- Say 6 numbers, one at a time. Each new number is one more than the one before.28, 29, 30, 31, 32, 33
- Write the numbers in order. Write each number you said.28, 29, 30, 31, 32, 33
Check. Count back from 33 to 27 with your finger. The same numbers come again. ✓
Watch out. Do not say 27 again. Start with the number after it.
Key words. To count on is to say the next numbers in order, one more each time.
Method. Start at 58. Say the next number each time, one at a time.
- Start at 58. Put your finger on the number you start from.Start: 58
- Say 3 numbers, one at a time. Each new number is one more than the one before.59, 60, 61
- Write the numbers in order. Write each number you said.59, 60, 61
Check. Count back from 61 to 58 with your finger. The same numbers come again. ✓
Watch out. Do not say 58 again. Start with the number after it.