1. 23 × 54
1242

2. 2.3 × 5.4 = × 54 10
How do we know these are the same? Writing decimals as fractions can help us to multiply them more easily. What is the answer to this calculation? How do we multiply these fractions? 1242/100 = 12.42

3. 0.23 × 54
So we know we want the numerators to be 23 and 54, because we already multiplied those together. So 23/? X 54/?

4. 1.8 × 0.26
How can we change these into fractions? We want to have integers on the top, so we could have 18/10 x 26/100. So we are going to need to know the answers to 18 x 26 (468)

5. 0.18 × 26
What shall we do if one of the numbers is already an integer?

6. 0.4 × = ×

7. 2.58 × 32 = × 32 1
If one of the numbers is already a whole number, that’s not a problem. You can think of it as a fraction over 1.

8. 2.52 × 0.6
Review steps. Make into fractions. Use long multiplication to multiply the integers. Divide by the overall power of 10.

9. 0.4 × 31.5
2.9 × 0.31
26 × 0.55

10. 0.4 × 31.5
12.6
2.9 × 0.31
0.899
26 × 0.55
14.3

11. Given that: 19 × 55 = 1045 Calculate 1.9 × 550
19 × 55 = 1045
Calculate
1.9 × 550
So they have given us something that looks helpful, but when we make these into fractions, we are probably going to want to know the answer to 19 x 550… how can we work that out from the information that we have been given? Answer to question: 1045 (one number is ten times smaller, the other is ten times bigger).

12. Given that: 35 × 66 = 2310 Calculate 350 × 6.6
35 × 66 = 2310
Calculate
350 × 6.6
Still 2310, one bigger, one smaller.

13. Given that:
14 × 2600 =
Calculate
1.4 × 26
Answer = 36.4