En anglais

Multiplying and Dividing Bigger Numbers

Mathématiques · Multiplication et division · de 7 à 8 ans

Nom ______________________ Date ____________

What is 23 x 4?
Réponse : ______________
Which partition correctly finds 23 x 4?
- 23 + 23 + 23
- 20 + 4 + 3 + 4
- 30 x 4 - 3 x 4
- 20 x 4 + 3 x 4
To multiply 23 × 4 by partitioning, you split 23 into two parts. What are they?
- 20 and 3
- 2 and 3
- 23 and 4
In the formal written method, you multiply the ones digit first.
En entourer un : Vrai Faux
Use partitioning to work out 34 x 2. What is the answer?
Réponse : ______________
You are multiplying 23 × 4 with the column method. You start with 3 × 4 = 12. What do you do?
- Write 12 in the ones place
- Write 1 in the ones place and carry the 2
- Write 2 in the ones place and carry the 1
Which table fact helps you work out 96 / 8?
- 9 x 8 = 72
- 8 x 12 = 96
- 8 + 8 = 16
- 96 - 8 = 88
Sam lays out 23 x 4 in columns, starting with the ones. Is that a good formal layout?
En entourer un : Vrai Faux
Mia works out 23 × 4 like this: 20 × 4 = 80, so the answer is 80. What mistake did she make?
- 20 × 4 should have been 60
- She forgot to add the 3 × 4 part, which is 12
- She used the wrong times table
Use a formal written layout to work out 45 x 3. What is the answer?
Réponse : ______________

Corrigé

Pour les adultes. Replier cette page avant de passer le reste.

92 · 20 x 4 = 80 and 3 x 4 = 12, so 80 + 12 = 92.
20 x 4 + 3 x 4 · 23 splits into 20 and 3, so 23 x 4 = 80 + 12 = 92.
20 and 3 · 23 has 2 tens and 3 ones, so it splits into 20 and 3.
Vrai · Short multiplication starts in the ones column, then moves to the tens.
68 · 30 x 2 = 60 and 4 x 2 = 8, so 60 + 8 = 68.
Write 2 in the ones place and carry the 1 · 12 has 1 ten and 2 ones. Write the 2 and carry the 1 ten into the next column.
8 x 12 = 96 · 8 x 12 = 96 shows that 96 splits into 8 groups of 12.
Vrai · Sam is good. Columns by place value with ones first keep regrouping safe.
She forgot to add the 3 × 4 part, which is 12 · Partitioning needs both parts added together: 80 + 12 = 92, not just 80.
135 · 3 x 5 = 15 (write 5, regroup 1), then 3 x 4 + 1 = 13, so 135.