5．口算
0 164157 164165 164171 164175 164181 164183 164187 164193 164195 164201 164207 164211 164213 164217 164223 164225 164231 164235 164237 164241 164243 164247 164249 164251 164252 164253 164255 164256 164257 164259 164261 164265 164267 164271 164273 164277 164283 164285 164291 164295 164297 164301 164307 164313 164315 164321 164325 164327 164333 164337 164343 164351 199269
| 0.34×5= | 16×0.01= | 1.78÷0.2= | 0.01÷0.1= |
| 1.8×20= | s-0.5s= | 20t-5t-3t= | 0.27÷0.003= |
| 3a+a= | x-0.4x= | 5d-2d= | 3.6÷0.4= |