Step-by-step Maths Level 5: Carrying tens from the ones column
Part of the Step-by-step Maths Level 5 long multiplication of two-digit by one-digit numbers chapter. Chapter overview · whole chapter on one page
Carrying tens from the ones column
When the ones product is ten or more, write the ones digit and carry the tens to the tens column.
Then multiply the tens digit and add the carried number before you write the tens digit.
Key ideas
- Write the ones digit; carry the tens.
- Multiply the tens, then add the carried number.
- Estimate first to check the answer is the right size.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 6. Write 8 in the ones column and carry 4 to the tens column.8 × 6 = 48
- Multiply the tens digit by 6. Write 2 in the tens column and carry 2 to the hundreds column.3 × 6 = 18, plus 4 carried = 22
- Write the carried number in front. The carried number is the next digit on the left.2 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.228
Check. Check: 228 ÷ 6 = 38.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 4. Write 8 in the ones column and carry 2 to the tens column.7 × 4 = 28
- Multiply the tens digit by 4. Write 2 in the tens column and carry 2 to the hundreds column.5 × 4 = 20, plus 2 carried = 22
- Write the carried number in front. The carried number is the next digit on the left.2 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.228
Check. Check: 228 ÷ 4 = 57.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Round to a number that is easy to multiply, then calculate.
- Round 38 to the nearest 10. Look at the ones digit: 5 or more rounds up.38 is about 40
- Multiply the rounded number. Use a fact we know from the tables.40 × 6 = 240
- Write the estimate. The exact answer should be close to this.240
Check. The exact answer is 228, which is close to 240.
Watch out. An estimate is not the exact answer. It tells you whether the exact answer is about the right size.
Watch out
Watch out. Do not forget to add the carried number to the tens product. 38 × 6: 3 tens × 6 = 18, plus 4 carried = 22 tens.
Exam tip
Grown-up tip. Ask: “Did you add the carried number? Is the answer about the estimate?”
Exercise 4B Practice: carrying from the ones
Non-calculatorMethod. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 2. Write 4 in the ones column.2 × 2 = 4
- Multiply the tens digit by 2. Write 6 in the tens column and carry 1 to the hundreds column.8 × 2 = 16
- Write the carried number in front. The carried number is the next digit on the left.1 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.164
Check. Check: 164 ÷ 2 = 82.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 8. Write 4 in the ones column and carry 6 to the tens column.8 × 8 = 64
- Multiply the tens digit by 8. Write 4 in the tens column and carry 5 to the hundreds column.6 × 8 = 48, plus 6 carried = 54
- Write the carried number in front. The carried number is the next digit on the left.5 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.544
Check. Check: 544 ÷ 8 = 68.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 5. Write 5 in the ones column and carry 4 to the tens column.9 × 5 = 45
- Multiply the tens digit by 5. Write 4 in the tens column and carry 1 to the hundreds column.2 × 5 = 10, plus 4 carried = 14
- Write the carried number in front. The carried number is the next digit on the left.1 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.145
Check. Check: 145 ÷ 5 = 29.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 7. Write 7 in the ones column.1 × 7 = 7
- Multiply the tens digit by 7. Write 9 in the tens column and carry 4 to the hundreds column.7 × 7 = 49
- Write the carried number in front. The carried number is the next digit on the left.4 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.497
Check. Check: 497 ÷ 7 = 71.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 2. Write 4 in the ones column.2 × 2 = 4
- Multiply the tens digit by 2. Write 2 in the tens column and carry 1 to the hundreds column.6 × 2 = 12
- Write the carried number in front. The carried number is the next digit on the left.1 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.124
Check. Check: 124 ÷ 2 = 62.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 5. Write 0 in the ones column and carry 4 to the tens column.8 × 5 = 40
- Multiply the tens digit by 5. Write 4 in the tens column and carry 3 to the hundreds column.6 × 5 = 30, plus 4 carried = 34
- Write the carried number in front. The carried number is the next digit on the left.3 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.340
Check. Check: 340 ÷ 5 = 68.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 6. Write 4 in the ones column and carry 2 to the tens column.4 × 6 = 24
- Multiply the tens digit by 6. Write 8 in the tens column.1 × 6 = 6, plus 2 carried = 8
- Write the answer. Read the digits from the bottom of each column, from the left.84
Check. Check: 84 ÷ 6 = 14.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 6. Write 6 in the ones column and carry 3 to the tens column.6 × 6 = 36
- Multiply the tens digit by 6. Write 5 in the tens column and carry 1 to the hundreds column.2 × 6 = 12, plus 3 carried = 15
- Write the carried number in front. The carried number is the next digit on the left.1 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.156
Check. Check: 156 ÷ 6 = 26.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 6. Write 6 in the ones column and carry 3 to the tens column.6 × 6 = 36
- Multiply the tens digit by 6. Write 7 in the tens column and carry 2 to the hundreds column.4 × 6 = 24, plus 3 carried = 27
- Write the carried number in front. The carried number is the next digit on the left.2 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.276
Check. Check: 276 ÷ 6 = 46.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 6. Write 4 in the ones column and carry 2 to the tens column.4 × 6 = 24
- Multiply the tens digit by 6. Write 0 in the tens column and carry 2 to the hundreds column.3 × 6 = 18, plus 2 carried = 20
- Write the carried number in front. The carried number is the next digit on the left.2 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.204
Check. Check: 204 ÷ 6 = 34.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 5. Write 5 in the ones column and carry 4 to the tens column.9 × 5 = 45
- Multiply the tens digit by 5. Write 4 in the tens column and carry 3 to the hundreds column.6 × 5 = 30, plus 4 carried = 34
- Write the carried number in front. The carried number is the next digit on the left.3 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.345
Check. Check: 345 ÷ 5 = 69.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 5. Write 0 in the ones column and carry 4 to the tens column.8 × 5 = 40
- Multiply the tens digit by 5. Write 9 in the tens column and carry 2 to the hundreds column.5 × 5 = 25, plus 4 carried = 29
- Write the carried number in front. The carried number is the next digit on the left.2 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.290
Check. Check: 290 ÷ 5 = 58.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 5. Write 5 in the ones column and carry 3 to the tens column.7 × 5 = 35
- Multiply the tens digit by 5. Write 8 in the tens column and carry 2 to the hundreds column.5 × 5 = 25, plus 3 carried = 28
- Write the carried number in front. The carried number is the next digit on the left.2 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.285
Check. Check: 285 ÷ 5 = 57.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 3. Write 2 in the ones column and carry 1 to the tens column.4 × 3 = 12
- Multiply the tens digit by 3. Write 2 in the tens column and carry 2 to the hundreds column.7 × 3 = 21, plus 1 carried = 22
- Write the carried number in front. The carried number is the next digit on the left.2 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.222
Check. Check: 222 ÷ 3 = 74.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 4. Write 0 in the ones column and carry 2 to the tens column.5 × 4 = 20
- Multiply the tens digit by 4. Write 6 in the tens column and carry 2 to the hundreds column.6 × 4 = 24, plus 2 carried = 26
- Write the carried number in front. The carried number is the next digit on the left.2 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.260
Check. Check: 260 ÷ 4 = 65.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.
Method. Multiply each digit by the number, starting with the ones. Carry the tens to the next column.
- Multiply the ones digit by 5. Write 5 in the ones column and carry 2 to the tens column.5 × 5 = 25
- Multiply the tens digit by 5. Write 2 in the tens column and carry 2 to the hundreds column.4 × 5 = 20, plus 2 carried = 22
- Write the carried number in front. The carried number is the next digit on the left.2 in the hundreds column
- Write the answer. Read the digits from the bottom of each column, from the left.225
Check. Check: 225 ÷ 5 = 45.
Watch out. Add any carried number before you write the digit of that column. Carry the tens; do not write them as a digit.