# Double-Double Strategy When Multiplying By 4

When multiplying by 4 you can use the strategy of double-double. For example, if the problem was 4 x 15, you double 15 (30) and then double 30, which equals 60.

Try solving some of these by using the double-double strategy and post your working out and answers in a comment under this post.

1) 4 x 18
2) 4 x 34
3) 4 x 62
4) 4 x 223

## 6 thoughts on “Double-Double Strategy When Multiplying By 4”

1. leigham says:

4×18 18 36 4×18=36
4×34 34 68 4×34=68
4×62 62 124 4×62=124
4×223 233 466 4×233=466

2. leigham says:

1) 4×18 = 72
(18×2=36) (36×2=72)
2) 4×34 = 36
(34×2=68) (68×2=136)
3)4×62 = 248
(62×2=124) (124×2=248)
4)4×223 = 932
(233×2=466) (466×2=932)

3. Jay says:

1) 18+18= 36+36 =72
72
2) 34+34=68+68=136
136
3) 62+62=124+124=248
248
4) 223+223=446+446=892
892

4. cody macdonald says:

4×18=72 18+18=36 36+36=72
4×34= 136 34+34=68 68+68=136
4×62=248 62+62=124 124+124=248
4×223=892 223+223=446 446+446=892

5. logan says:

18×4=72 18×2=36 36×2=72 Therefor 18×4=72.
4×34=136 34×2=68 68×2=136 Therefor 4×34=136.
4×62=248 62×2=124 2×124=248 Therefor 4×62=248.
4×223=892 223×2=446 446×2=892 Therefor 4×233=892.

6. Carissa says: