Lesson · Grade 4 · Mathematics
Break a number apart to multiply
- Grade 4
- Mathematics
- 57 s
- British Columbia
- BC4-MA-10
The video works out 7 × 12 by showing 7 rows of 12 squares and breaking every row into 10 and 2, which gives 7 × 12 = 7 × 10 + 7 × 2. It lights up each part's rows to get 70 and 14, adds them to reach 84, and ends on the recap "Break it apart, multiply each part, then add".
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In one sentence
The question this lesson answers
What is 7 times 12?
Think of it as 7 rows, with 12 squares in each row.
Transcript
What the lesson says
What is 7 times 12?
Think of it as 7 rows, with 12 squares in each row.
12 is 10 plus 2, so break each row into 10 and 2.
Breaking the rows apart does not change how many squares there are.
So 7 times 12 is 7 times 10, plus 7 times 2.
7 rows of 10 make 70.
7 rows of 2 make 14.
Now add the two parts together.
70 plus 14 is 84.
So 7 times 12 is 84.
To multiply, break a number into easy parts, multiply each part, then add.
Curriculum
Where this fits
- British Columbia, Grade 4
Mathematics, Number: multiplication and division of two- or three-digit numbers by one-digit numbersBC4-MA-10
Previous: Estimating Sums and Differences by RoundingNext: Multiplying a three-digit number by a one-digit number with an area model
- British Columbia, Grade 5
Mathematics, Number: multiplication and division facts to 100 (emerging computational fluency)BC5-MA-20
Previous: Multiply by 4 and by 8 by doublingNext: Division facts from multiplication facts
- British Columbia, Grade 6
Mathematics, Number: multiplication and division facts to 100 (developing computational fluency)BC6-MA-04
Previous: Multiply by 4 and by 8 by doublingNext: Division facts from multiplication facts
- British Columbia, Grade 7
Mathematics, Number: multiplication and division facts to 100BC7-MA-04
Previous: Multiply by 9: Times 10, Then Take One Group AwayNext: Division facts from multiplication facts
This lesson is also listed in Grade 5, Grade 6 and Grade 7.
The outcomes and strands follow the British Columbia curriculum.
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