Reception Maths Numbers to 20: check-up and practice test questions

Key words. A teen number is one ten and some ones, for example 13 is one ten and three ones.

Method. A teen number is one ten and some ones. Ten is one full ten frame.

1. Find the ten. Ten is one full ten frame.
   1 ten = 10
2. Count the ones left over. The ones are the extra counters.
   16 − 10 = 6 ones
3. Write the answer. Say it as a ten and some ones.
   16 is one ten and 6 ones

Check. Ten and 6 more makes 16: 10 + 6 = 16. ✓

Watch out. The “ten” always comes first. Do not count the ten frame as ones.

Method. Read the whole number word. Then find it on the number list.

1. Read the word. Read every part, including the second half of a long word.
   “thirteen”
2. Find the word on the list. Each word matches one number.
   thirteen = 13
3. Write the numeral. A numeral uses digits.
   13

Check. Count 13 things in your head, then check the numeral. ✓

Watch out. Look at the whole word. Thirteen and thirty look alike but are different.

Method. Say the number, then write its name in words.

1. Look at the numeral. Find it on the number list.
   15
2. Find its name. Every number has one name.
   15 = fifteen
3. Write the word. Write each letter in order.
   fifteen

Check. Read the word back. It has the same number of things as 15. ✓

Watch out. Check the spelling. Thirteen, fourteen and fifteen are different words.

Method. Find 18 on the number track. The number after it is the answer.

1. Find 18. Put your finger on it.
   18
2. Move one box to the right. Each box is one more or one less.
   18 + 1 = 19
3. Write the answer.
   19

Check. Check it: 19 − 1 = 18. ✓

Watch out. Move one box only. Do not write the number you started with.

Method. Find 14 on the number track. The number before it is the answer.

1. Find 14. Put your finger on it.
   14
2. Move one box to the left. Each box is one more or one less.
   14 − 1 = 13
3. Write the answer.
   13

Check. Check it: 13 + 1 = 14. ✓

Watch out. Move one box only. Do not write the number you started with.

Method. The number between 11 and 13 is in the middle of them.

1. Find 11 and 13. Put your fingers on both numbers.
   11 ... 13
2. Count on one from 11. The middle number is one more than the first.
   11 + 1 = 12
3. Write the answer.
   12

Check. Count on from 12 to 13: 12 + 1 = 13. ✓

Watch out. The number between is not one of the two you started with.

Method. Each number is one more than the number before. Use the numbers you can see to find the gaps.

1. Look at the numbers around each gap. Counting on means each number is one more.
   4, ?, 6, 7, ?, 9
2. Add one to the number before each gap. That gives the missing number.
   Gap 2: 4 + 1 = 5
   Gap 5: 7 + 1 = 8
3. Write the missing numbers.
   5, 8

Check. Read the whole line again. Every number is one more than the one before. ✓

Watch out. Check the numbers after the gap too. They should still go up by one.

Method. Start at 17 and count back to 14. Each number is one less than the one before.

1. Start at 17. Start with the biggest number.
   17
2. Count back to 14. Each number is one less.
   17, 16, 15, 14
3. Write the numbers. Include the first and last numbers.
   17, 16, 15, 14

Check. Count on from 14 to 17 to check. ✓

Watch out. Count back one at a time. Do not jump over a number.

Method. Smallest first. Look at how many tens each number has, then the ones.

1. Look at the tens of each number. More tens means a bigger number.
   19, 12, 15
2. Put the smallest first. Then put the next smallest.
   12, 15, 19
3. Write the numbers in order. Check you have not left one out.
   12, 15, 19

Check. There are 3 numbers in the question and 3 in the answer. ✓

Watch out. Compare the tens first. Only look at the ones if the tens are the same.

Method. Use the ten frame idea: one full frame, then the extras.

1. Take one full frame. A full frame is ten.
   10
2. Count the extras. Nine counters are left over.
   9 ones
3. Add them together. Ten and nine more make 19.
   10 + 9 = 19
4. Write the answer.
   Accept any answer that says 10 is one ten and 9 more ones make 19.

Check. Count on from 10: 11, 12, ... 19. ✓

Watch out. Start with the full ten, then count the ones.

Key words. A teen number is one ten and some ones, for example 13 is one ten and three ones.

Method. A teen number is one ten and some ones. Ten is one full ten frame.

1. Find the ten. Ten is one full ten frame.
   1 ten = 10
2. Count the ones left over. The ones are the extra counters.
   13 − 10 = 3 ones
3. Write the answer. Say it as a ten and some ones.
   13 is one ten and 3 ones

Check. Ten and 3 more makes 13: 10 + 3 = 13. ✓

Watch out. The “ten” always comes first. Do not count the ten frame as ones.

Method. Read the whole number word. Then find it on the number list.

1. Read the word. Read every part, including the second half of a long word.
   “eighteen”
2. Find the word on the list. Each word matches one number.
   eighteen = 18
3. Write the numeral. A numeral uses digits.
   18

Check. Count 18 things in your head, then check the numeral. ✓

Watch out. Look at the whole word. Thirteen and thirty look alike but are different.

Method. Find 16 on the number track. The number after it is the answer.

1. Find 16. Put your finger on it.
   16
2. Move one box to the right. Each box is one more or one less.
   16 + 1 = 17
3. Write the answer.
   17

Check. Check it: 17 − 1 = 16. ✓

Watch out. Move one box only. Do not write the number you started with.

Method. Each number is one more than the number before. Use the numbers you can see to find the gaps.

1. Look at the numbers around each gap. Counting on means each number is one more.
   9, ?, 11, ?, 13
2. Add one to the number before each gap. That gives the missing number.
   Gap 2: 9 + 1 = 10
   Gap 4: 11 + 1 = 12
3. Write the missing numbers.
   10, 12

Check. Read the whole line again. Every number is one more than the one before. ✓

Watch out. Check the numbers after the gap too. They should still go up by one.

Method. Start at 17 and count on to 20. Each number is one more than the one before.

1. Start at 17. Say the first number.
   17
2. Count on to 20. Say each number, one more each time.
   17, 18, 19, 20
3. Write the numbers. Write them in order.
   17, 18, 19, 20

Check. Count back from 20 to 17. You say the same numbers in reverse. ✓

Watch out. Do not skip a number. Check each one is one more than the last.

Method. Smallest first. Look at how many tens each number has, then the ones.

1. Look at the tens of each number. More tens means a bigger number.
   16, 11, 14
2. Put the smallest first. Then put the next smallest.
   11, 14, 16
3. Write the numbers in order. Check you have not left one out.
   11, 14, 16

Check. There are 3 numbers in the question and 3 in the answer. ✓

Watch out. Compare the tens first. Only look at the ones if the tens are the same.

Method. Break 14 into a ten and some ones.

1. Take one ten. A ten is 10.
   10
2. Add the ones. Four ones make the rest of 14.
   10 + 4
3. Check the total. Ten and four is fourteen.
   10 + 4 = 14
4. Write the answer.
   Yes. 14 is one ten and four ones, because 10 + 4 = 14.

Check. Count on from 10: 11, 12, 13, 14. ✓

Watch out. Start from the ten, not from 1.

Method. Count on one at a time, then look at the number after the last one.

1. Start at 25. Say each number after it.
   25
2. Count on to 28. Each number is one more.
   25, 26, 27, 28
3. Find the next number. One more than 28 is 29.
   28 + 1 = 29
4. Write the answer.
   25, 26, 27, 28. After 28 comes 29.

Check. Count back from 29 to 25 to check. ✓

Watch out. The number after 28 is 29.

Method. Start with what Lily has. Then add the 2 more ones.

1. Start with 1 ten and 6 ones. That is 16.
   10 + 6 = 16
2. Add 2 more ones. Count on from 16: 17, 18.
   16, 17, 18
3. Say it as a ten and some ones. Ten and eight ones make 18.
   10 + 8 = 18
4. Write the answer.
   18. There is one ten and eight ones.

Check. Count back 2 from 18: 17, 16. ✓

Watch out. Count on from 16, one at a time.

Method. Think about the ones digit. It goes 0 to 9 and then a new ten starts.

1. Look at 0 to 10. Ones go 0 to 9, then 10 starts a new ten.
   0 to 9, then 10
2. Look at 20 to 30. The ones go 0 to 9, then 30 starts a new ten.
   20 to 29, then 30
3. Give an example. The same pattern happens at every ten.
   29, then 30
4. Write the answer.
   Accept any answer that says the ones go 0 to 9 in each ten, then the next ten starts, for example 29 then 30.

Check. Count 9 to 10 and 29 to 30. The same pattern. ✓

Watch out. The ones start again from 0 in each new ten.