2 tens − ⬜ ones = 12 

1. Represent the math sentence using numbers: 20−⬜ = 12 

2. Find the unknown number:

⬜ = 20−12;

20−12=8

3. Put the answer in the math sentence instead of the gap: 2 tens − 8 ones = 12

⬜ tens + ⬜ ones = 19

1. The first number on the left denotes tens. The number 19 contains one ten.

2. The first digit on the right is the place for ones. There are 9 ones in the number 19.

3. Fill in the gaps in the math sentence: 1 ten+ 9 ones = 19. 

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Write down one ten using numbers. We write tens on the second place on the right, and on the ones place will be 0: 10. It is possible to represent 10 as a sum of even numbers and ones: 10+0=10 - it is one ten and 0 ones.

Let’s solve the following expression: 1 ten + 8 ones = ⬜ 

1. First, we need to write down this math sentence using numbers. 1 ten is 10. 8 ones is 8.

Thus, we get: 10+8=⬜ 

2. Let’s solve the math sentence: 10+8. When we add up the ten and one-digit numbers, the number of tens remains the same, and the one-digit number takes the ones place: 10+8=18.

3. Then we can write the result in the following way: 1 ten + 8 ones = 18

How can we find the value of the following expression? 2 tens - 7 ones = ⬜

1. It is possible to represent this expression as a math sentence: 2 tens is 20, 7 ones = 7.

Thus, we get 20-7=⬜

2. Let’s find the difference: 20-7. 20=10+10. Then we can subtract 7 from the first ten and add to the second ten.

10-7=3

10+3=13

3. Now, we can write the result as the expression: 2 tens - 7 ones = 13 

Let’s solve this expression: 2 tens - ⬜ ones = 14

1. First, write down the math sentence: 2 tens = 20. We need to find the number of ones which after subtracting from 20 gives 14. Let’s denote it as: 20 -⬜=14

2. Then, we need to find out the unknown number: 20-⬜=14. The whole number is 20 and one of the parts is 14. We need to find the second part. To do this, subtract the part from the whole: 20-14. We get 6.

3. We put this number in the expression given at the beginning: 2 tens - 6 ones = 14

Can you find the unknown numbers in the expression given below? ⬜ tens + ⬜ ones = 19

In this expression, we need to find the tens and ones of the number 19 and fill in the gaps.

1. The tens place is the first on the left, that is 1 in 19. Let’s put it at the given expression: 1 ten + ⬜ ones = 19.

2. The ones place is the first on the right. The number of ones in 19 equals 9. Let’s add this number to our expression: 1 ten + 9 ones = 19.

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